Percutaneous closure of a post-traumatic ventricular septal defect with a patent ductus arteriosus occluder

PubMed Central

Xi, Er-Ping; Zhu, Jian; Zhu, Shui-Bo; Yin, Gui-Lin; Liu, Yong; Dong, Yong-Qiang; Zhang, Yu; Xia, Feng

2012-01-01

OBJECTIVE: Ventricular septal defects resulting from post-traumatic cardiac injury are very rare. Percutaneous closure has emerged as a method for treating this disorder. We wish to report our experience in three patients who underwent percutaneous closure of a post-traumatic ventricular septal defect with a patent ductus arteriosus occluder. METHODS: We treated three patients with post-traumatic ventricular septal defects caused by stab wounds with knives. After the heart wound was repaired, patient examinations revealed ventricular septal defects with pulmonary/systemic flow ratios (Qp/Qs) of over 1.7. The post-traumatic ventricular septal defects were closed percutaneously with a patent ductus arteriosus occluder (Lifetech Scientific (Shenzhen) Co., LTD, Guangdong, China) utilizing standard techniques. RESULTS: Post-operative transthoracic echocardiography revealed no residual left-to-right shunt and indicated normal ventricular function. In addition, 320-slice computerized tomography showed that the occluder was well placed and exhibited normal morphology. CONCLUSION: Our experiences indicate that closure of a post-traumatic ventricular septal defect using a patent ductus arteriosus occluder is feasible, safe, and effective. PMID:23184204

β1-Adrenoceptor blocker aggravated ventricular arrhythmia.

PubMed

Wang, Yan; Patel, Dimpi; Wang, Dao Wu; Yan, Jiang Tao; Hsia, Henry H; Liu, Hao; Zhao, Chun Xia; Zuo, Hou Juan; Wang, Dao Wen

2013-11-01

To assess the impact of β1 -adrenoceptor blockers (β1 -blocker) and isoprenaline on the incidence of idiopathic repetitive ventricular arrhythmia that apparently decreases with preprocedural anxiety. From January 2010 to July 2012, six patients were identified who had idiopathic ventricular arrhythmias that apparently decreased (by greater than 90%) with preprocedural anxiety. The number of ectopic ventricular beats per hour (VPH) was calculated from Holter or telemetry monitoring to assess the ectopic burden. The mean VPH of 24 hours from Holter before admission (VPH-m) was used as baseline (100%) for normalization. β1 -Blockers, isoprenaline, and/or aminophylline were administrated successively on the ward and catheter lab to evaluate their effects on the ventricular arrhythmias. Among 97 consecutive patients with idiopathic ventricular arrhythmias, six had reduction in normalized VPHs in the hour before the scheduled procedure time from (104.6 ± 4.6%) to (2.8 ± 1.6%) possibly due to preprocedural anxiety (P < 0.05), then increased to (97.9 ± 9.7%) during β1 -blocker administration (P < 0.05), then quickly reduced to (1.6 ± 1.0%) during subsequent isoprenaline infusion. Repeated β1 -blocker quickly counteracted the inhibitory effect of isoprenaline, and VPHs increased to (120.9 ± 2.4%) from (1.6 ± 1.0%; P < 0.05). Isoprenaline and β1 -blocker showed similar effects on the arrhythmias in catheter lab. In some patients with structurally normal heart and ventricular arrhythmias there is a marked reduction of arrhythmias associated with preprocedural anxiety. These patients exhibit a reproducible sequence of β1 -blocker aggravation and catecholamine inhibition of ventricular arrhythmias, including both repetitive ventricular premature beats and monomorphic ventricular tachycardia. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

Metaiodobenzylguanidine (/sup 131/I) scintigraphy detects impaired myocardial sympathetic neuronal transport function of canine mechanical-overload heart failure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rabinovitch, M.A.; Rose, C.P.; Rouleau, J.L.

1987-12-01

In heart failure secondary to chronic mechanical overload, cardiac sympathetic neurons demonstrate depressed catecholamine synthetic and transport function. To assess the potential of sympathetic neuronal imaging for detection of depressed transport function, serial scintigrams were acquired after the intravenous administration of metaiodobenzylguanidine (/sup 131/I) to 13 normal dogs, 3 autotransplanted (denervated) dogs, 5 dogs with left ventricular failure, and 5 dogs with compensated left ventricular hypertrophy due to a surgical arteriovenous shunt. Nine dogs were killed at 14 hours postinjection for determination of metaiodobenzylguanidine (/sup 131/I) and endogenous norepinephrine content in left atrium, left ventricle, liver, and spleen. By 4more » hours postinjection, autotransplanted dogs had a 39% reduction in mean left ventricular tracer accumulation, reflecting an absent intraneuronal tracer pool. Failure dogs demonstrated an accelerated early mean left ventricular tracer efflux rate (26.0%/hour versus 13.7%/hour in normals), reflecting a disproportionately increased extraneuronal tracer pool. They also showed reduced late left ventricular and left atrial concentrations of tracer, consistent with a reduced intraneuronal tracer pool. By contrast, compensated hypertrophy dogs demonstrated a normal early mean left ventricular tracer efflux rate (16.4%/hour) and essentially normal late left ventricular and left atrial concentrations of tracer. Metaiodobenzylguanidine (/sup 131/I) scintigraphic findings reflect the integrity of the cardiac sympathetic neuronal transport system in canine mechanical-overload heart failure. Metaiodobenzylguanidine (/sup 123/I) scintigraphy should be explored as a means of early detection of mechanical-overload heart failure in patients.« less

Left ventricular function in Friedreich's ataxia. An echocardiographic study.

PubMed Central

Sutton, M G; Olukotun, A Y; Tajik, A J; Lovett, J L; Giuliani, E R

1980-01-01

Left ventricular function was assessed in seven patients with Friedreich's ataxia using computer-assisted analysis of the left ventricular echocardiograms and compared with those of 45 normal children matched for age and sex. The left ventricle in Friedreich's ataxia was symmetrically hypertrophied, cavity dimension was normal or small, and septal motion and peak velocity of circumferential shortening were normal in all patients. In diastole the duration of rapid filling was normal, peak rate of increase in left ventricular dimension was reduced in two patients, mitral valve opening was delayed with respect to minimum cavity dimension in seven, and there were significantly greater than normal increases in left ventricular dimension during the isovolumic period to mitral valve opening in seven, indicating abnormal and incoordinate relaxation. Peak rates of posterior wall systolic thickening and diastolic thinning were reduced in four and six patients, respectively, whereas peak rates of septal systolic thickening and diastolic thinning were reduced in one and four, respectively, suggesting a disproportionately greater impairment of the posterior wall than of septal function. The absence of asymmetric septal hypertrophy and mid-systolic closure of the aortic valve, the presence of normal septal motion, and the greater reduction in posterior wall than in septal dynamics are inconsistent with previous ideas that the heart disease of Friedreich's ataxia is identical to hypertrophic cardiomyopathy. Computer-assisted analysis of echocardiograms permits recognition of heart disease in Friedreich's ataxia before the onset of cardiac symptoms or development of clinical signs of heart disease. Images PMID:7426188

Recurrent Takotsubo Cardiomyopathy Related to Recurrent Thyrotoxicosis.

PubMed

Patel, Keval; Griffing, George T; Hauptman, Paul J; Stolker, Joshua M

2016-04-01

Takotsubo cardiomyopathy, or transient left ventricular apical ballooning syndrome, is characterized by acute left ventricular dysfunction caused by transient wall-motion abnormalities of the left ventricular apex and mid ventricle in the absence of obstructive coronary artery disease. Recurrent episodes are rare but have been reported, and several cases of takotsubo cardiomyopathy have been described in the presence of hyperthyroidism. We report the case of a 55-year-old woman who had recurrent takotsubo cardiomyopathy, documented by repeat coronary angiography and evaluations of left ventricular function, in the presence of recurrent hyperthyroidism related to Graves disease. After both episodes, the patient's left ventricular function returned to normal when her thyroid function normalized. These findings suggest a possible role of thyroid-hormone excess in the pathophysiology of some patients who have takotsubo cardiomyopathy.

Monitoring ventricular function at rest and during exercise with a nonimaging nuclear detector.

PubMed

Wagner, H N; Rigo, P; Baxter, R H; Alderson, P O; Douglass, K H; Housholder, D F

1979-05-01

A portable nonimaging device, the nuclear stethoscope, for measuring beat to beat ventricular time-activity curves in normal people and patients with heart disease, both at rest and during exercise, is being developed and evaluated. The latest device has several operating modes that facilitate left ventricular and background localization, measurement of transit times and automatic calculation and display of left ventricular ejection fraction. The correlation coefficient of left ventricular ejection fraction obtained with the device and with a camera-computer system was 0.92 in 35 subjects. During bicycle exercise the ejection fraction in 15 normal persons increased from 44 to 64 percent (P less than 0.001), whereas among 12 patients with heart disease it was unchanged in 5 and decreased in 7.

Reduction of ventricular size after shunting for normal pressure hydrocephalus related to CSF dynamics before shunting.

PubMed Central

Tans, J T; Poortvliet, D C

1988-01-01

Reduction of ventricular size was determined by repeated computed tomography in 30 adult patients shunted for normal pressure hydrocephalus (NPH) and related to the pressure-volume index (PVI) and resistance to outflow of cerebrospinal fluid (Rcsf) measured before shunting. Rapid and marked reduction of ventricular size (n = 10) was associated with a significantly lower PVI than slow and moderate to marked (n = 13) or minimal to mild reduction (n = 7). Otherwise no relationship could be found between the reduction of ventricular size and PVI or Rcsf. It is concluded that both rate and magnitude of reduction of ventricular size after shunting for NPH are extremely variable. High brain elasticity seems to be the best predictor of rapid and marked reduction. PMID:3379425

The effect of acetyl strophanthidin on the hearts of normal dogs.

PubMed

Hayes, A H; McShane, W P; Sidell, F R

1970-05-01

1. The ED50 of acetyl strophanthidin for producing ventricular arrhythmias in normal dogs was 54.5 mug/kg intravenously.2. Doses up to and including those which caused ventricular tachycardia did not produce either atrial arrhythmias or significant aberration of A-V conduction.3. Although the classic digitalis-induced rate and e.c.g. waveform changes may appear after administration of acetyl strophanthidin, their presence or absence have no value in predicting the subsequent development of ventricular arrhythmias.

Ventricular fibrillation induced by coagulating mode bipolar electrocautery during pacemaker implantation in Myotonic Dystrophy type 1 patient.

PubMed

Russo, Vincenzo; Rago, Anna; DI Meo, Federica; Cioppa, Nadia Della; Papa, Andrea Antonio; Russo, Maria Giovanna; Nigro, Gerardo

2014-12-01

The occurrence of ventricular fibrillation, induced by bipolar electrocautery during elective dual chamber pacemaker implantation, is reported in a patient affected by Myotonic Distrophy type 1 with normal left ventricular ejection fraction.

Cardiac function in children with premature ventricular contractions: the effect of omega-3 polyunsaturated fatty acid supplementation.

PubMed

Oner, Taliha; Ozdemir, Rahmi; Doksöz, Onder; Genc, Dildar B; Guven, Baris; Demirpence, Savas; Yilmazer, Murat M; Yozgat, Yilmaz; Mese, Timur; Tavli, Vedide

2018-07-01

Premature ventricular contractions are accepted as benign in structurally normal hearts. However, reversible cardiomyopathy can sometimes develop. Omega-3 polyunsaturated fatty acids have anti-arrhythmic properties in animals and humans.AimWe evaluated left ventricular function in children with premature ventricular contractions with normal cardiac anatomy and assessed the impact of omega-3 fatty acid supplementation on left ventricular function in a prospective trial. A total of 25 patients with premature ventricular contraction, with more than 2% premature ventricular contractions on 24-hour Holter electrocardiography, and 30 healthy patients were included into study. All patients underwent electrocardiography, left ventricular M-mode echocardiography, and myocardial performance index testing. Patients with premature ventricular contraction were given omega-3 fatty acids at a dose of 1 g/day for 3 months, and control echocardiography and 24-hour Holter electrocardiography were performed. Neither placebo nor omega-3 fatty acids were given to the control group. Compared with the values of the control group, the patients with premature ventricular contraction had significantly lower fractional shortening. The myocardial performance index decreased markedly in the patient groups. The mean heart rate and mean premature ventricular contraction percentage of Group 2 significantly decreased in comparison with their baseline values after the omega-3 supplementation. In conclusion, premature ventricular contractions can lead to systolic cardiac dysfunction in children. Omega-3 supplementation may improve cardiac function in children with premature ventricular contractions. This is the first study conducted in children to investigate the possible role of omega-3 fatty acid supplementation on treatment of premature ventricular contractions.

Amiodarone therapy in chronic heart failure and myocardial infarction: a review of the mortality trials with special attention to STAT-CHF and the GESICA trials. Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina.

PubMed

Pinto, J V; Ramani, K; Neelagaru, S; Kown, M; Gheorghiade, M

1997-01-01

Amiodarone appears to reduce sudden death in patients with left ventricular dysfunction resulting from an acute MI or a primary dilated cardiomyopathy, particularly if complex ventricular arrhythmias are present. Amiodarone's beneficial effect on mortality in these patients could be unrelated to its antiarrhythmic effects. Multiple factors could account for the improvement in mortality such as the drug's antiischemic effects, neuromodulating effects, its effect on left ventricular function and on heart rate. Moreover, patients with LV dysfunction who have survived an episode of sudden death would potentially benefit from amiodarone therapy. Future trials are needed to determine the precise subsets(s) of patients who would benefit from the drug and the most efficacious dosing regimen for the drug. Based on available data, amiodarone is the only antiarrhythmic agent which has not been shown to increase mortality in patients with chronic heart failure.

Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum.

PubMed

Martini, Bortolo; Trevisi, Nicola; Martini, Nicolò; Zhang, Li

2015-01-01

A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT). ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI) revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches.

Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum

PubMed Central

Martini, Bortolo; Trevisi, Nicola; Martini, Nicolò; Zhang, Li

2015-01-01

A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT). ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI) revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches. PMID:26509086

Cardiovascular Magnetic Resonance Findings Late After the Arterial Switch Operation.

PubMed

Shepard, Charles W; Germanakis, Ioannis; White, Matthew T; Powell, Andrew J; Co-Vu, Jennifer; Geva, Tal

2016-09-01

Despite its robust diagnostic capabilities in adolescents and adult patients after the arterial switch operation, little information is available on the cardiovascular magnetic resonance findings in this population. The cardiovascular magnetic resonance findings of 220 consecutive patients evaluated in our center were retrospectively reviewed (median age at cardiovascular magnetic resonance, 15.4 years; 66.8% male sex). Compared with published normal values, left and right ventricular end-diastolic volume z scores were mildly enlarged (0.48±1.76 and 0.33±1.5; P=0.0003 and 0.0038, respectively), with 26% of patients having left ventricular dilatation and 20% having right ventricular dilatation. Left ventricular dysfunction was present in 21.5% of patients (mild in most), and only 5.1% of patients had mild right ventricular dysfunction. Myocardial scar was found in 1.8% of patients. Dilatation of the neoaortic root was common (76%), and root z score increased at an average rate of 0.03 points per year. By multivariable analysis, neoaortic root dilatation was associated with worse neoaortic valve regurgitation (OR, 5.29; P=0.0016). The diameters of the thoracic aorta distal to the root were near-normal in most patients, whereas the neomain pulmonary artery was typically oval shaped with decreased anteroposterior and normal lateral diameters. Although the majority of arterial switch operation patients have normal ventricular size and function and myocardial scar is rare, an important minority exhibits ventricular enlargement or dysfunction. Neoaortic root dilatation, which is present in most patients and progresses over time, is strongly associated with significant neoaortic valve regurgitation. The findings of this study provide reference values against which arterial switch operation patients can be compared with their peers. © 2016 American Heart Association, Inc.

Mitral annulus motion as determined by M-mode echocardiography in normal dogs and dogs with cardiac disease.

PubMed

Schober, K E; Fuentes, V L

2001-01-01

M-mode echocardiography was used to assess apical mitral annulus motion (MAM) in 103 normal dogs and 101 dogs with cardiac disease, to obtain information on systolic left ventricular long axis function. In normal dogs, a close relationship was found between MAM and body weight (r = 0.80, P < 0.001). There was a weak correlation between MAM and heart rate (r = -0.25, P < 0.05), but no correlation between MAM and age or left ventricular shortening fraction (P > 0.05). Mean MAM (95% confidence intervals) were established for normal dogs of differing body weight, and were 0.70 cm (0.65 to 0.75) in dogs < 15 kg, 1.08 cm (1.03 to 1.13) in dogs weighing 15 to 40 kg, and 1.51 cm (1.21 to 1.81) in dogs > 40 kg. "Cut-off" values to define decreased MAM for normal dogs of differing body weight were 0.45 cm (dogs < 15 kg), 0.80 cm (dogs 15-40 kg), and 1.20 cm (dogs > 40 kg). In dogs with cardiac disease, median MAM was normal in mitral valve endocardiosis or aortic stenosis, but significantly decreased (P < 0.05) in dilated cardiomyopathy. All dogs with mitral valve endocardiosis (n = 54) or aortic stenosis (n = 26) had MAM above the above-mentioned "cut-off" values, suggesting normal or increased left ventricular longitudinal systolic shortening, whereas 81% (17/21) of dogs with dilated cardiomyopathy had MAM below the "cut-off" value, indicating decreased long axis systolic function. It is concluded that MAM may be used to evaluate systolic left ventricular long axis performance in dogs and may add useful information on global left ventricular contraction dynamics.

The Cardiovascular Effects of Obesity on Ventricular Function and Mass in Patients after Tetralogy of Fallot Repair.

PubMed

Fogel, Mark A; Pawlowski, Thomas; Keller, Marc S; Cohen, Meryl S; Goldmuntz, Elizabeth; Diaz, Laura; Li, Christine; Whitehead, Kevin K; Harris, Matthew A

2015-08-01

To determine the cardiovascular effects of obesity on patients with tetralogy of Fallot (TOF) repair. Ventricular performance measures were compared between obese (body mass index [BMI] ≥95%), overweight (85% ≤BMI <95%), and normal weight subjects (BMI <85%) in a retrospective review of patients with TOF who underwent cardiac magnetic resonance from 2005-2010. Significance was P < .05. Of 260 consecutive patients with TOF, 32 were obese (12.3%), 48 were overweight (18.5%), and 180 were normal weight (69.2%). Biventricular mass was increased in obese compared with normal weight patients with right ventricular mass more affected than left ventricular mass. Obese patients demonstrated decreased biventricular end-diastolic volume (EDV) and stroke volume (SV) when indexed to body surface area (BSA) with an increased heart rate when compared with normal weight patients; cardiac index, ejection fraction, and pulmonary regurgitation fraction were similar. When indexed to ideal BSA, biventricular EDV and SV were similar. EDV and SV for overweight patients were nearly identical to normal weight patients with ventricular mass in between the other 2 groups. Approximately 12% of patients after TOF repair referred for cardiac magnetic resonance in a tertiary referral center are obese with increased biventricular mass. Obese patients and normal weight patients have similar cardiac indices, however, when indexed to actual BSA, obese patients demonstrate decreased EDV and SV with increased heart rate and similar cardiac indices. When indexed to ideal BSA, no differences in biventricular volumes were noted. Copyright © 2015. Published by Elsevier Inc.

Integration of mechanical, structural and electrical imaging to understand response to cardiac resynchronization therapy.

PubMed

Silva, Etelvino; Bijnens, Bart; Berruezo, Antonio; Mont, Lluis; Doltra, Adelina; Andreu, David; Brugada, Josep; Sitges, Marta

2014-10-01

There is extensive controversy exists on whether cardiac resynchronization therapy corrects electrical or mechanical asynchrony. The aim of this study was to determine if there is a correlation between electrical and mechanical sequences and if myocardial scar has any relevant impact. Six patients with normal left ventricular function and 12 patients with left ventricular dysfunction and left bundle branch block, treated with cardiac resynchronization therapy, were studied. Real-time three-dimensional echocardiography and electroanatomical mapping were performed in all patients and, where applicable, before and after therapy. Magnetic resonance was performed for evaluation of myocardial scar. Images were postprocessed and mechanical and electrical activation sequences were defined and time differences between the first and last ventricular segment to be activated were determined. Response to therapy was defined as a reduction in left ventricular end-systolic volume ≥ 15% after 12 months of follow-up. Good correlation between electrical and mechanical timings was found in patients with normal left ventricular function (r(2) = 0.88; P = .005) but not in those with left ventricular dysfunction (r(2) = 0.02; P = not significant). After therapy, both timings and sequences were modified and improved, except in those with myocardial scar. Despite a close electromechanical relationship in normal left ventricular function, there is no significant correlation in patients with dysfunction. Although resynchronization therapy improves this correlation, the changes in electrical activation may not yield similar changes in left ventricular mechanics particularly depending on the underlying myocardial substrate. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Fibrosis-Related Gene Expression in Single Ventricle Heart Disease.

PubMed

Nakano, Stephanie J; Siomos, Austine K; Garcia, Anastacia M; Nguyen, Hieu; SooHoo, Megan; Galambos, Csaba; Nunley, Karin; Stauffer, Brian L; Sucharov, Carmen C; Miyamoto, Shelley D

2017-12-01

To evaluate fibrosis and fibrosis-related gene expression in the myocardium of pediatric subjects with single ventricle with right ventricular failure. Real-time quantitative polymerase chain reaction was performed on explanted right ventricular myocardium of pediatric subjects with single ventricle disease and controls with nonfailing heart disease. Subjects were divided into 3 groups: single ventricle failing (right ventricular failure before or after stage I palliation), single ventricle nonfailing (infants listed for primary transplantation with normal right ventricular function), and stage III (Fontan or right ventricular failure after stage III). To evaluate subjects of similar age and right ventricular volume loading, single ventricle disease with failure was compared with single ventricle without failure and stage III was compared with nonfailing right ventricular disease. Histologic fibrosis was assessed in all hearts. Mann-Whitney tests were performed to identify differences in gene expression. Collagen (Col1α, Col3) expression is decreased in single ventricle congenital heart disease with failure compared with nonfailing single ventricle congenital heart disease (P = .019 and P = .035, respectively), and is equivalent in stage III compared with nonfailing right ventricular heart disease. Tissue inhibitors of metalloproteinase (TIMP-1, TIMP-3, and TIMP-4) are downregulated in stage III compared with nonfailing right ventricular heart disease (P = .0047, P = .013 and P = .013, respectively). Matrix metalloproteinases (MMP-2, MMP-9) are similar between nonfailing single ventricular heart disease and failing single ventricular heart disease, and between stage III heart disease and nonfailing right ventricular heart disease. There is no difference in the prevalence of right ventricular fibrosis by histology in subjects with single ventricular failure heart disease with right ventricular failure (18%) compared with those with normal right ventricular function (38%). Fibrosis is not a primary contributor to right ventricular failure in infants and young children with single ventricular heart disease. Additional studies are required to understand whether antifibrotic therapies are beneficial in this population. Copyright © 2017 Elsevier Inc. All rights reserved.

Ventricular arrhythmias in the absence of structural heart disease.

PubMed

Prystowsky, Eric N; Padanilam, Benzy J; Joshi, Sandeep; Fogel, Richard I

2012-05-15

Ventricular arrhythmia (VA) in structurally normal hearts can be broadly considered under non-life-threatening monomorphic and life-threatening polymorphic rhythms. Monomorphic VA is classified on the basis of site of origin in the heart, and the most common areas are the ventricular outflow tracts and left ventricular fascicles. The morphology of the QRS complexes on electrocardiogram is an excellent tool to identify the site of origin of the rhythm. Although these arrhythmias are common and generally carry an excellent prognosis, rare sudden death events have been reported. Very frequent ventricular ectopy may also result in a cardiomyopathy in a minority of patients. Suppression of VA may be achieved using calcium-channel blockers, beta-adrenergic blockers, and class I or III antiarrhythmic drugs. Radiofrequency ablation has emerged as an excellent option to eliminate these arrhythmias, although certain foci including aortic cusps and epicardium may be technically challenging. Polymorphic ventricular tachycardia (VT) is rare and generally occurs in patients with genetic ion channel disorders including long QT syndrome, Brugada syndrome, catecholaminergic polymorphic VT, and short QT syndrome. Unlike monomorphic VT, these arrhythmic syndromes are associated with sudden death. While the cardiac gross morphology is normal, suggesting a structurally normal heart, abnormalities exist at the molecular level and predispose them to arrhythmias. Another fascinating area, idiopathic ventricular fibrillation and early repolarization syndrome, are undergoing research for a genetic basis. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Correlation between cardiac remodelling, function, and myocardial contractility in rat hearts 5 weeks after myocardial infarction.

PubMed

Gosselin, H; Qi, X; Rouleau, J L

1998-01-01

Early after infarction, ventricular dysfunction occurs as a result of loss of myocardial tissue. Although papillary muscle studies suggest that reduced myocardial contractility contributes to this ventricular dysfunction, in vivo studies indicate that at rest, cardiac output is normal or near normal, suggesting that contractility of the remaining viable myocardium of the ventricular wall is preserved. However, this has never been verified. To explore this further, 100 rats with various-sized myocardial infarctions had ventricular function assessed by Langendorff preparation or by isolated papillary muscle studies 5 weeks after infarction. Morphologic studies were also done. Rats with large infarctions (54%) had marked ventricular dilatation (dilatation index from 0.23 to 0.75, p < 0.01) and papillary muscle dysfunction (total tension from 6.7 to 3.2 g/mm2, p < 0.01) but only moderate left ventricular dysfunction (maximum developed tension from 206 to 151 mmHg (1 mmHg = 133.3 Pa), p < 0.01), a decrease less than one would expect with an infarct size of 54%. The contractility of the remaining viable myocardium of the ventricle was also moderately depressed (peak systolic midwall stress 91 to 60 mmHg, p < 0.01). Rats with moderate infarctions (32%) had less marked but still moderate ventricular dilatation (dilatation index 0.37, p < 0.001) and moderate papillary muscle dysfunction (total tension 4.2 g/mm2, p < 0.01). However, their decrease in ventricular function was only mild (maximum developed pressure 178 mmHg, p < 0.01) and less than one would expect with an infarct size of 32%. The remaining viable myocardium of the ventricular wall appeared to have normal contractility (peak systolic midwall stress = 86 mmHg, ns). We conclude that in this postinfarction model, in large myocardial infarctions, a loss of contractility of the remaining viable myocardium of the ventricular wall occurs as early as 5 weeks after infarction and that papillary muscle studies slightly overestimate the degree of ventricular dysfunction. In moderate infarctions, the remaining viable myocardium of the ventricular wall has preserved contractility while papillary muscle function is depressed. In this relatively early postinfarction phase, ventricular remodelling appears to help maintain left ventricular function in both moderate and large infarctions.

[Acute left ventricular systolic dysfunction after pericardial effusion drainage].

PubMed

Brauner, F B; Nunes, C E; Fabra, R; Riesgo, A; Thomé, L G

1997-12-01

A patient with a thymoma and initially normal ventricular systolic function developed cardiac tamponade, which was relieved by pericardiocentesis. After four days, the tumor was removed and, one week after the relief of tamponade, she developed severe left ventricular systolic dysfunction, that recovered in three days with venous therapy.

Detection of premature ventricular contractions on a ventricular electrocardiogram for patients with left ventricular assist devices.

PubMed

Park, Sung Min; Lee, Jin Hong; Choi, Seong Wook

2014-12-01

The ventricular electrocardiogram (v-ECG) was developed for long-term monitoring of heartbeats in patients with a left ventricular assist device (LVAD) and does not normally have the functionality necessary to detect additional heart irregularities that can progress to critical arrhythmias. Although the v-ECG has the benefits of physiological optimization and counterpulsation control, when abnormal heartbeats occur, the v-ECG does not show the distinct abnormal waveform that enables easy detection of an abnormal heartbeat among normal heartbeats on the conventional ECG. In this study, the v-ECGs of normal and abnormal heartbeats are compared with each other with respect to peak-to-peak voltage, area, and maximal slopes, and a new method to detect abnormal heartbeats is suggested. In a series of animal experiments with three porcine models (Yorkshire pigs weighing 30-40 kg), a v-ECG and conventional ECG were taken simultaneously during LVAD perfusion. Clinical experts found 104 abnormal heartbeats from the saved conventional ECG data and confirmed that the other 3159 heartbeats were normal. Almost all of the abnormal heartbeats were premature ventricular contractions (PVCs), and there was short-term tachycardia for 3 s. A personal computer was used to automatically detect abnormal heartbeats with the v-ECG according to the new method, and its results were compared with the clinicians' results. The new method found abnormal heartbeats with 90% accuracy, and less than 15% of the total PVCs were missed. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Ventricular myoarchitecture in tetralogy of Fallot.

PubMed Central

Sanchez-Quintana, D.; Anderson, R. H.; Ho, S. Y.

1996-01-01

BACKGROUND: Little attention has been paid to the architecture of the muscle fibres of the ventricular walls in congenitally malformed hearts. In this study the gross pattern of myocardial fibres in normal hearts was compared with that in cases of tetralogy of Fallot. METHODS AND RESULTS: After morphological examination nine specimens with tetralogy were dissected to study the ventricular myoarchitecture. Changes were found in the shape of the malformed ventricles. The ventricular walls were arranged in layers in all hearts. Superficial and deep layers were present in both ventricles, with the superficial layer showing a more oblique orientation in the specimens with tetralogy than in normal hearts. Modifications of muscle fibre that were related to the type of malformation were seen in the deep layer. A middle layer was present in the left ventricles of normal hearts and specimens with tetralogy: this showed a horizontal orientation in both groups. In contrast, a middle layer was found in the right ventricle only in specimens showing tetralogy. CONCLUSIONS: The malformed hearts showed modifications in ventricular shape, in the arrangement of muscle in the right ventricle, and in the overall myoarchitecture. These changes could well be the consequence of the same agent (or agents) that caused the structural defect. Images PMID:8868990

PubMed Central

RUSSO, VINCENZO; RAGO, ANNA; DI MEO, FEDERICA; CIOPPA, NADIA DELLA; PAPA, ANDREA ANTONIO; RUSSO, MARIA GIOVANNA

2014-01-01

The occurrence of ventricular fibrillation, induced by bipolar electrocautery during elective dual chamber pacemaker implantation, is reported in a patient affected by Myotonic Distrophy type 1 with normal left ventricular ejection fraction PMID:25873784

Systolic ventricular filling.

PubMed

Torrent-Guasp, Francisco; Kocica, Mladen J; Corno, Antonio; Komeda, Masashi; Cox, James; Flotats, A; Ballester-Rodes, Manel; Carreras-Costa, Francesc

2004-03-01

The evidence of the ventricular myocardial band (VMB) has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium, making it possible to understand the principles governing electrical, mechanical and energetical events within the human heart. From the earliest Erasistratus' observations, principal mechanisms responsible for the ventricular filling have still remained obscured. Contemporary experimental and clinical investigations unequivocally support the attitude that only powerful suction force, developed by the normal ventricles, would be able to produce an efficient filling of the ventricular cavities. The true origin and the precise time frame for generating such force are still controversial. Elastic recoil and muscular contraction were the most commonly mentioned, but yet, still not clearly explained mechanisms involved in the ventricular suction. Classical concepts about timing of successive mechanical events during the cardiac cycle, also do not offer understandable insight into the mechanism of the ventricular filling. The net result is the current state of insufficient knowledge of systolic and particularly diastolic function of normal and diseased heart. Here we summarize experimental evidence and theoretical backgrounds, which could be useful in understanding the phenomenon of the ventricular filling. Anatomy of the VMB, and recent proofs for its segmental electrical and mechanical activation, undoubtedly indicates that ventricular filling is the consequence of an active muscular contraction. Contraction of the ascendent segment of the VMB, with simultaneous shortening and rectifying of its fibers, produces the paradoxical increase of the ventricular volume and lengthening of its long axis. Specific spatial arrangement of the ascendent segment fibers, their interaction with adjacent descendent segment fibers, elastic elements and intra-cavitary blood volume (hemoskeleton), explain the physical principles involved in this action. This contraction occurs during the last part of classical systole and the first part of diastole. Therefore, the most important part of ventricular diastole (i.e. the rapid filling phase), in which it receives >70% of the stroke volume, belongs to the active muscular contraction of the ascendent segment. We hope that these facts will give rise to new understanding of the principal mechanisms involved in normal and abnormal diastolic heart function.

Asynchronous (segmental early) relaxation impairs left ventricular filling in patients with coronary artery disease and normal systolic function.

PubMed

Vanoverschelde, J L; Wijns, W; Michel, X; Cosyns, J; Detry, J M

1991-11-01

Asynchronous segmental early relaxation, defined as a localized early segmental outward motion of the left ventricular endocardium during isovolumetric relaxation, has been associated with an altered left ventricular relaxation rate. To determine whether asynchronous segmental early relaxation also results in impaired left ventricular filling, early diastolic ventricular wall motion and Doppler-derived left ventricular filling indexes were examined in 25 patients with documented coronary artery disease and normal systolic function. Patients were further classified into two groups according to the presence (n = 15, group 1) or absence (n = 10, group 2) of asynchronous early relaxation at left ventriculography. A third group of 10 age-matched normal subjects served as a control group. No differences were observed between the two patient groups with coronary artery disease with respect to age, gender distribution, heart rate, left ventricular systolic and diastolic pressures or extent and severity of coronary artery disease. No differences in transmitral filling dynamics were observed between group 2 patients and age-matched control subjects. Conversely, group 1 patients had significantly lower peak early filling velocities (44 +/- 11 vs. 58 +/- 11 cm/s, p less than 0.01), larger atrial filling fraction (45 +/- 4% vs. 38 +/- 4%, p less than 0.001), lower ratio of early to late transmitral filling velocities (0.6 +/- 0.08 vs. 0.99 +/- 0.18, p less than 0.001) and a longer isovolumetric relaxation period (114 +/- 12 vs. 90 +/- 6 ms, p less than 0.001) compared with group 2 patients and control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

[Assessment of left ventricular twist in type 2 diabetes mellitus by using two-dimensional ultrasound speckle tracking imaging].

PubMed

Zhu, Pei-hua; Huang, Jing-yuan; Ye, Meng; Zheng, Zhe-lan

2014-09-01

To evaluate the left ventricular twist characteristics in patients with type 2 diabetes by using two-dimensional speckle tracking imaging (STI). Ninety-three patients with type 2 diabetes admitted in Zhejiang Hospital from May 2012 to September 2013 were enrolled. According to left ventricular ejection fraction (LVEF), patients were divided into two groups: normal left ventricular systolic function group (group A, LVEF≥0.50, n=46) and abnormal left ventricular systolic function group (group B, LVEF <0.50, n=47). Forty-six healthy subjects were selected as normal controls. STI was applied to quantitatively analyze the left ventricular twist. Correlation of the peak of left ventricular twist angle (Peaktw), aortic valve closure time twist angle (AVCtw), and mitral valve opening time twist angle (MVOtw) with LVEF, Tei index, E/A, and E/e was evaluated. Consistency check for STI was conducted to assess its stability and reliability. The Peaktw, AVCtw, and MVOtw in group A were significantly elevated than those in normal controls (P<0.05). The Peaktw, AVCtw, and MVOtw in group B was lower than those in normal controls and group A (P<0.05). In diabetic patients, the Peaktw, AVCtw, MVOtw were positively correlated with LVEF (r=0.968, 0.966, 0.938;P<0.05) and E/A (r=0.798, 0.790, 0.788; P<0.05), and were negatively correlated with Tei index (r=-0.834, -0.811, -0.797; P<0.05) and E/e (r=-0.823, -0.805, -0.771; P<0.05). The agreement between measurers and within measurers of Peaktw was satisfactory (between measurers: R=0.957, bias=-0.1, 95% consistency limit=-2.8-2.7; within measurer: R=0.964, bias=-0.2, 95% consistency limits=-2.7-2.2). STI can be used for early recognition of abnormal changes of cardiac function in type 2 diabetic mellitus patients, with high stability and reliability.

STAR (Simple Targeted Arterial Rendering) Technique: a Novel and Simple Method to Visualize the Fetal Cardiac Outflow Tracts

PubMed Central

Yeo, Lami; Romero, Roberto; Jodicke, Cristiano; Kim, Sun Kwon; Gonzalez, Juan M.; Oggè, Giovanna; Lee, Wesley; Kusanovic, Juan Pedro; Vaisbuch, Edi; Hassan, Sonia S.

2010-01-01

Objective To describe a novel and simple technique (STAR: Simple Targeted Arterial Rendering) to visualize the fetal cardiac outflow tracts from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView). Methods We developed a technique to image the outflow tracts by drawing three dissecting lines through the four-chamber view of the heart contained in a STIC volume dataset. Each line generated the following plane: 1) Line 1: ventricular septum “en face” with both great vessels (pulmonary artery anterior to the aorta); 2) Line 2: pulmonary artery with continuation into the longitudinal view of the ductal arch; and 3) Line 3: long axis view of the aorta arising from the left ventricle. The pattern formed by all 3 lines intersecting approximately through the crux of the heart resembles a “star”. The technique was then tested in 50 normal hearts (15.3 – 40.4 weeks of gestation). To determine if the technique could identify planes that departed from the normal images, we tested the technique in 4 cases with proven congenital heart defects (ventricular septal defect, transposition of great vessels, tetralogy of Fallot, and pulmonary atresia with intact ventricular septum). Results The STAR technique was able to generate the intended planes in all 50 normal cases. In the abnormal cases, the STAR technique allowed identification of the ventricular septal defect, demonstrated great vessel anomalies, and displayed views that deviated from what was expected from the examination of normal hearts. Conclusions This novel and simple technique can be used to visualize the outflow tracts and ventricular septum “en face” in normal fetal hearts. The inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease involving the great vessels and/or the ventricular septum. The STAR technique may simplify examination of the fetal heart and could reduce operator dependency. PMID:20878672

Right Ventricular Myocardial Ischemia with Arrhythmia in an Asphyxiated Newborn

PubMed Central

Solevåg, Anne Lee; Schmölzer, Georg M.; Cheung, Po-Yin

2016-01-01

Background Infant and neonatal myocardial infarction (MI) has been described in association with congenital heart disease, coronary artery abnormalities, myocarditis, and tumors. MI in the perinatal period in a structurally normal heart and with ventricular arrhythmia as a presenting feature has not been thoroughly described. Published case reports describe treatment methods extrapolated from adult MI. However, due to the rare occurrence, the most appropriate acute treatment for both MI and ventricular arrhythmia in newborn infants remains unknown. Case A male term infant with perinatal asphyxia and need for extensive cardiopulmonary resuscitation at birth had ventricular tachyarrhythmia and ST-elevations on electrocardiogram. Four hours after birth, he died from cardiogenic failure. A thrombus at the right coronary artery was found on autopsy. Conclusion MI in the perinatal period in a structurally normal heart is very rare and mortality is high. Although acute treatments extrapolated from adult MI has been described to result in favorable outcomes in newborn infants, guidelines are lacking on how to manage acute MI and associated ventricular arrhythmia. PMID:27280062

Echocardiographic left ventricular masses in distance runners and weight lifters

NASA Technical Reports Server (NTRS)

Longhurst, J. C.; Gonyea, W. J.; Mitchell, J. H.; Kelly, A. R.

1980-01-01

The relationships of different forms of exercise training to left ventricular mass and body mass are investigated by echocardiographic studies of weight lifters, long-distance runners, and comparatively sized untrained control subjects. Left ventricular mass determinations by the Penn convention reveal increased absolute left ventricular masses in long-distance runners and competitive weight lifters with respect to controls matched for age, body weight, and body surface area, and a significant correlation between ventricular mass and lean body mass. When normalized to lean body mass, the ventricular masses of distance runners are found to be significantly higher than those of the other groups, suggesting that dynamic training elevates left ventricular mass compared to static training and no training, while static training increases ventricular mass only to the extent that lean body mass is increased.

Prevalence of lateral ventricle asymmetry in brain MRI studies of neurologically normal dogs and dogs with idiopathic epilepsy.

PubMed

Pivetta, Mauro; De Risio, Luisa; Newton, Richard; Dennis, Ruth

2013-01-01

Asymmetry of the cerebral lateral ventricles is a common finding in cross-sectional imaging of otherwise normal canine brains and has been assumed to be incidental. The purpose of this retrospective study was to compare the prevalence of ventricular asymmetry in brain MRI studies of normal dogs and dogs with idiopathic epilepsy. Brain MRI archives were searched for 100 neurologically normal dogs (Group 1) and 100 dogs with idiopathic epilepsy (Group 2). For each dog, asymmetry of the lateral ventricles was subjectively classified as absent, mild, moderate, and severe based on a consensus of two observers who were unaware of group status. Ventricular areas were measured from transverse T1W images at the level of the interthalamic adhesion. An asymmetry ratio was calculated as the ratio of the larger to smaller ventricular transverse area. There was excellent agreement between subjective assessments of ventricular asymmetry and quantitative assessments using asymmetry ratios (k = 0.995). The prevalence of asymmetry was 38% in Group 1 dogs and 44% in Group 2 dogs. Assymmetry was scored as mild in the majority of Group 2 dogs. There was no significant association between presence/absence and degree of ventricular asymmetry vs. dog group, age, gender, or skull conformation. Findings from the current study supported previously published assumptions that asymmetry of the lateral cerebral ventricles is an incidental finding in MRI studies of the canine brain. © 2013 Veterinary Radiology & Ultrasound.

Ventricular fibrillation in an ambulatory patient supported by a left ventricular assist device: highlighting the ICD controversy.

PubMed

Boilson, Barry A; Durham, Lucian A; Park, Soon J

2012-01-01

Left ventricular assist devices (LVADs) provide an effective means of managing advanced pump failure as a means of bridging to cardiac transplantation or as permanent therapy. Although ventricular arrhythmias remain common post-LVAD implantation, such therapy may allow malignant arrhythmias to be tolerated hemodynamically. This report describes the clinical findings in a patient who had likely been in a ventricular tachyarrhythmia for several days and presented in ventricular fibrillation, ambulatory, and mentating normally. This report, with previous similar reports, is additive to the body of evidence that LVADs alter the physiologic impact of ventricular arrhythmias in advanced heart failure and highlights the need for thoughtful programming of implantable cardioverter defibrillator therapies in these patients.

Left ventricular geometric patterns in newly presenting nigerian hypertensives: An echocardiographic study

PubMed Central

Aje, Akinyemi; Adebiyi, Adewole A; Oladapo, Olulola O; Dada, Adekola; Ogah, Okechukwu S; Ojji, Dike B; Falase, Ayodele O

2006-01-01

Background Hypertension is a global problem and it is prevalent in Nigeria. Left ventricular hypertrophy is a major complication of hypertension with risk of sudden death and arrhythmias among others. Abnormal left ventricular geometric patterns also increase the burden of morbidity and mortality. It is therefore important to know the different left ventricular geometric patterns in Nigerian hypertensives because of their prognostic significance. Methods One hundred (100) newly presenting hypertensives (53 males and 47 females) and 100 controls (53 males and 47 females) were recruited for the study. All were subjected to clinical evaluation and full echocardiographic examination was performed according to the ASE recommendation. The relative wall thickness and the presence or absence of echocardiographic left ventricular hypertrophy were used to determine the various geometric patterns Results The mean age of the hypertensive subjects was 56.06 (± 7.68) years while that of the control subjects was 56.10 (± 7.68) years. There was no significant difference in the mean ages of the two groups. In the hypertensive subjects 28% had normal geometry, 26% had concentric remodeling, 28% had concentric hypertrophy and 18% had eccentric hypertrophy. In the control group, 86% had normal geometry, 11% had concentric remodeling, 3% had eccentric hypertrophy and none had concentric hypertrophy. There was statistical significance when the geometric patterns of the hypertensive and controls were compared (χ2 = 74.30, p value < 0.0001). Conclusion The study showed that only 28% of the hypertensive subjects had normal LV geometric pattern while 86% of the normal subjects had normal geometry. There is need for longitudinal studies in order to prognosticate the various geometric patterns. PMID:16426452

Right Ventricular Hemodynamics in Patients with Pulmonary Hypertension

NASA Astrophysics Data System (ADS)

Browning, James; Fenster, Brett; Hertzberg, Jean; Schroeder, Joyce

2012-11-01

Recent advances in cardiac magnetic resonance imaging (CMR) have allowed for characterization of blood flow in the right ventricle (RV), including calculation of vorticity and circulation, and qualitative visual assessment of coherent flow patterns. In this study, we investigate qualitative and quantitative differences in right ventricular hemodynamics between subjects with pulmonary hypertension (PH) and normal controls. Fifteen (15) PH subjects and 10 age-matched controls underwent same day 3D time resolved CMR and echocardiography. Echocardiography was used to determine right ventricular diastolic function as well as pulmonary artery systolic pressure (PASP). Velocity vectors, vorticity vectors, and streamlines in the RV were visualized in Paraview and total RV Early (E) and Atrial (A) wave diastolic vorticity was quantified. Visualizations of blood flow in the RV are presented for PH and normal subjects. The hypothesis that PH subjects exhibit different RV vorticity levels than normals during diastole is tested and the relationship between RV vorticity and PASP is explored. The mechanics of RV vortex formation are discussed within the context of pulmonary arterial pressure and right ventricular diastolic function coincident with PH.

Successful weaning of a left ventricular assist device implanted for ischemic heart failure.

PubMed

Beurtheret, Sylvain; Mordant, Pierre; Pavie, Alain; Leprince, Pascal

2010-10-01

We report the case of a patient stabilized under extra-corporeal membrane oxygenation after a refractory cardiogenic shock following myocardial infarction. Persistent left ventricular failure required secondary implantation of the left ventricular assist device (LVAD) HeartMate II. LVAD succeeded in the gradual recovery of myocardial contractility, allowing weaning of the device five months after implantation. Simultaneously, the patient beneficiated from coronary revascularization and resumed normal activity. This case emphasizes potential late recoveries after myocardial infarction complicated by left ventricular failure.

Ventricular, but not atrial, M2-muscarinic receptors increase in the canine pacing-overdrive model of heart failure.

PubMed

Wilkinson, M; Giles, A; Armour, J A; Cardinal, R

1996-01-01

To investigate the effects of heart failure induced by chronic rapid ventricular pacing (six weeks) on canine atrial and ventricular muscarinic receptors. Dogs (n = 4) were fitted with a bipolar pacing electrode connected to a Medtronic pacemaker set at 240 stimuli/min. Pacing was maintained for six weeks. Tissue samples obtained from the left atrium and ventral wall of the left ventricle were frozen at -70 degrees C. Control tissue was obtained from normal dogs (n = 6) following anesthesia and thoracotomy. M2-muscarinic receptors were characterized and quantified in tissue micropunches using the hydrophilic ligand [3H] N-methyl-scopolamine (NMS). Cardiac tissue bound [3H] NMS with the specificity of an M2 subtype. Tachycardia-induced heart failure did not affect atrial muscarinic receptors but signify left ventricular myocytes (control 160.0 +/- 10.0 fmol/mg protein versus heart failure 245.0 +/- 25.0 fmol/mg protein; P < 0.01). Canine ventricular muscarinic receptors display a specificity for the M2 subtype. In contrast to previous work, tachycardia-induced heart failure was accompanied by an increase (+ 53%) in ventricular, but not atrial, M2 receptors compared with normal dogs.

Endurance sport and "cardiac injury": a prospective study of recreational ironman athletes.

PubMed

Leischik, Roman; Spelsberg, Norman

2014-09-03

Participation in triathlon competitions has increased in recent years. Many studies have described left or right ventricular injury in endurance athletes. The goal of this study was to examine the right and left ventricular cardiac structures and function and dynamic cardio-pulmonary performance in a large cohort of middle- and long-distance triathletes. 87 triathletes (54 male and 33 female) were examined using spiroergometry and echocardiography. The inclusion criterion was participation in at least one middle- or long distance triathlon. Male triathletes showed a maximum oxygen absorption of 58.1 ± 8.6 mL/min/kg (female triathletes 52.8 ± 5.7 mL/min/kg), maximum ergometer performance of 347.8 ± 49.9 W (female triathletes 264.5 ± 26.1 W). Left ventricular ejection fraction (EF) was normal (male triathletes EF: 61.9% ± 3%, female triathletes EF: 63.0% ± 2.7%) and systolic right ventricular area change fraction (RV AFC%) showed normal values (males RV AFC%: 33.5% ± 2.2%, females 32.2% ± 2.8%). Doppler indices of diastolic function were normal in both groups. With respect to the echocardiographic readings the left ventricular mass for males and females were 217.7 ± 41.6 g and 145.9 ± 31.3 g, respectively. The relative wall thickness for males was 0.50 ± 0.07, whereas it was 0.47 ± 0.09 for females. The probability of left ventricular mass >220 g increased with higher blood pressure during exercise (OR: 1.027, CI 1.002-1.052, p = 0.034) or with higher training volume (OR: 1.23, CI 1.04-1.47, p = 0.019). Right or left ventricular dysfunction could not be found, although the maximal participation in triathlon competitions was 29 years. A left ventricular mass >220 g is more likely to occur with higher arterial pressure during exercise and with a higher training volume.

Endurance Sport and “Cardiac Injury”: A Prospective Study of Recreational Ironman Athletes

PubMed Central

Leischik, Roman; Spelsberg, Norman

2014-01-01

Background: Participation in triathlon competitions has increased in recent years. Many studies have described left or right ventricular injury in endurance athletes. The goal of this study was to examine the right and left ventricular cardiac structures and function and dynamic cardio-pulmonary performance in a large cohort of middle- and long-distance triathletes. Methods: 87 triathletes (54 male and 33 female) were examined using spiroergometry and echocardiography. The inclusion criterion was participation in at least one middle- or long distance triathlon. Results: Male triathletes showed a maximum oxygen absorption of 58.1 ± 8.6 mL/min/kg (female triathletes 52.8 ± 5.7 mL/min/kg), maximum ergometer performance of 347.8 ± 49.9 W (female triathletes 264.5 ± 26.1 W). Left ventricular ejection fraction (EF) was normal (male triathletes EF: 61.9% ± 3%, female triathletes EF: 63.0% ± 2.7%) and systolic right ventricular area change fraction (RV AFC%) showed normal values (males RV AFC%: 33.5% ± 2.2%, females 32.2% ± 2.8%). Doppler indices of diastolic function were normal in both groups. With respect to the echocardiographic readings the left ventricular mass for males and females were 217.7 ± 41.6 g and 145.9 ± 31.3 g, respectively. The relative wall thickness for males was 0.50 ± 0.07, whereas it was 0.47 ± 0.09 for females. The probability of left ventricular mass >220 g increased with higher blood pressure during exercise (OR: 1.027, CI 1.002–1.052, p = 0.034) or with higher training volume (OR: 1.23, CI 1.04–1.47, p = 0.019). Conclusions: Right or left ventricular dysfunction could not be found, although the maximal participation in triathlon competitions was 29 years. A left ventricular mass >220 g is more likely to occur with higher arterial pressure during exercise and with a higher training volume. PMID:25192145

Assessment of left ventricular myocardial deformation by cardiac MRI strain imaging reveals myocardial dysfunction in patients with primary cardiac tumors.

PubMed

Chen, Jing; Yang, Zhi-Gang; Xu, Hua-Yan; Shi, Ke; Guo, Ying-Kun

2018-02-15

To assess left ventricular myocardial deformation in patients with primary cardiac tumors. MRI was retrospectively performed in 61 patients, including 31 patients with primary cardiac tumors and 30 matched normal controls. Left ventricular strain and function parameters were then assessed by MRI-tissue tracking. Differences between the tumor group and controls, left and right heart tumor groups, left ventricular wall tumor and non-left ventricular wall tumor groups, and tumors with and without LV enlargement groups were assessed. Finally, the correlations among tumor diameter, myocardial strain, and LV function were analyzed. Left ventricular myocardial strain was milder for tumor group than for normal group. Peak circumferential strain (PCS) and its diastolic strain rate, longitudinal strains (PLS) and its diastolic strain rates, and peak radial systolic and diastolic velocities of the right heart tumor group were lower than those of the left heart tumor group (all p<0.050), but the peak radial systolic strain rate of the former was higher than that of the latter (p=0.017). The corresponding strains were lower in the left ventricular wall tumor groups than in the non-left ventricular wall tumor group (p<0.050). Peak radial systolic velocities were generally higher for tumors with LV enlargement than for tumors without LV enlargement (p<0.050). Peak radial strain, PCS, and PLS showed important correlations with the left ventricular ejection fraction (all p<0.050). MRI-tissue tracking is capable of quantitatively assessing left ventricular myocardial strain to reveal sub-clinical abnormalities of myocardial contractile function. Copyright © 2017 Elsevier B.V. All rights reserved.

Cavopulmonary Anastomosis in a Patient With Arrhythmogenic Right Ventricular Cardiomyopathy With Severe Right Ventricular Dysfunction.

PubMed

Vaidyanathan, Swaminathan; Kothandam, Sivakumar; Kumar, Rajesh; Indrajith, Sujatha Desai; Agarwal, Ravi

2017-01-01

A 26-year-old lady presented with exertional dyspnea, palpitations, central cyanosis, and oxygen saturations of 80% in room air. Her electrocardiogram, echocardiogram, and cardiac magnetic resonance were diagnostic of arrhythmogenic right ventricular dysplasia. There was no documented ventricular arrhythmia or syncopal episodes and Holter recordings were repeatedly normal. Cardiac hemodynamics showed right to left shunt through atrial septal defect, low pulmonary blood flow, normal atrial pressures, and minimally elevated right ventricular end-diastolic pressures. Since her presenting symptoms and cyanosis were attributed to reduced pulmonary blood flow, she underwent off-pump cavopulmonary anastomosis between right superior vena cava and right pulmonary artery. As we intended to avoid the adverse effect of extracorporeal circulation on the myocardial function and pulmonary vasculature, we did not attempt to reduce the size of the atrial septal defect. Her postoperative period was uneventful; oxygen saturation improved to 89% with significant improvement in effort tolerance. At 18-month follow-up, there were no ventricular arrhythmias on surveillance. The clinical presentation of this disease may vary from serious arrhythmias warranting defibrillators and electrical ablations at one end to right ventricular pump failure warranting cardiomyoplasty or right ventricular exclusion procedures at the other end. However, when the presentation was unusual with severe cyanosis through a stretched foramen ovale leading to reduced pulmonary blood flows, Glenn shunt served as a good palliation and should be considered as one of the options in such patients.

Clinical significance of incomplete tricuspid valve closure seen on two-dimensional echocardiography.

PubMed

Gibson, T C; Foale, R A; Guyer, D E; Weyman, A E

1984-11-01

Incomplete closure of the tricuspid valve without apparent cusp disease was noted on two-dimensional echocardiography in 31 patients. This abnormality was defined as a failure of the tricuspid valve leaflet tips to reach the plane of the tricuspid valve anulus by at least 1 cm in the standard apical four chamber view at the point of maximal systolic closure. This resulted in a final systolic leaflet position deeper within the right ventricular cavity than is normally seen. The finding was present in the following diagnostic subgroups: Group A, pulmonary hypertension (11 patients); Group B, rheumatic heart disease (4 patients); Group C, dilated cardiomyopathy (9 patients) and Group D, previous myocardial infarction (7 patients). Right atrial, right ventricular and tricuspid anulus measurements were made and compared with those from a group of 67 normal subjects. The results were as follows: right atrial endsystolic area = 27.2 +/- 8.6 cm2 (normal = 13.4 +/- 2.0); right ventricular end-systolic area = 25.6 +/- 8.7 cm2 (normal = 10.9 +/- 2.9); right ventricular end-diastolic area = 31.5 +/- 9.1 cm2 (normal = 20.1 +/- 4.9) and tricuspid valve anular end-systolic dimension = 4.0 +/- 0.6 cm (normal = 2.2 +/- 0.3). The differences from the normal data were all statistically significant (p less than 0.001). Incomplete closure of the tricuspid valve, although a nonspecific diagnostic finding, is primarily associated with right-sided chamber enlargement. Tricuspid regurgitation may be present. The mechanism could be related to geometric changes in valve apparatus dynamics secondary to right-sided cardiac enlargement and tricuspid valve anular dilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Continuous-Flow Left Ventricular Assist Device Support Improves Myocardial Supply:Demand in Chronic Heart Failure.

PubMed

Soucy, Kevin G; Bartoli, Carlo R; Phillips, Dustin; Giridharan, Guruprasad A; Sobieski, Michael A; Wead, William B; Dowling, Robert D; Wu, Zhongjun J; Prabhu, Sumanth D; Slaughter, Mark S; Koenig, Steven C

2017-06-01

Continuous-flow left ventricular assist devices (CF LVADs) are rotary blood pumps that improve mean blood flow, but with potential limitations of non-physiological ventricular volume unloading and diminished vascular pulsatility. In this study, we tested the hypothesis that left ventricular unloading with increasing CF LVAD flow increases myocardial flow normalized to left ventricular work. Healthy (n = 8) and chronic ischemic heart failure (IHF, n = 7) calves were implanted with CF LVADs. Acute hemodynamics and regional myocardial blood flow were measured during baseline (LVAD off, clamped), partial (2-4 L/min) and full (>4 L/min) LVAD support. IHF calves demonstrated greater reduction of cardiac energy demand with increasing LVAD support compared to healthy calves, as calculated by rate-pressure product. Coronary artery flows (p < 0.05) and myocardial blood flow (left ventricle (LV) epicardium and myocardium, p < 0.05) decreased with increasing LVAD support in normal calves. In the IHF model, blood flow to the septum, LV, LV epicardium, and LV myocardium increased significantly with increasing LVAD support when normalized to cardiac energy demand (p < 0.05). In conclusion, myocardial blood flow relative to cardiac demand significantly increased in IHF calves, thereby demonstrating that CF LVAD unloading effectively improves cardiac supply and demand ratio in the setting of ischemic heart failure.

Right Ventricular Outflow Tract Septal Pacing Is Superior to Right Ventricular Apical Pacing

PubMed Central

Zou, Cao; Song, Jianping; Li, Hui; Huang, Xingmei; Liu, Yuping; Zhao, Caiming; Shi, Xin; Yang, Xiangjun

2015-01-01

Background The effects of right ventricular apical pacing (RVAP) and right ventricular outflow tract (RVOT) septal pacing on atrial and ventricular electrophysiology have not been thoroughly compared. Methods and Results To identify a more favorable pacing strategy with fewer adverse effects, 80 patients who had complete atrioventricular block with normal cardiac function and who were treated with either RVAP (n=42) or RVOT septal pacing (n=38) were recruited after an average of 2 years of follow‐up. The data from electrocardiography and echocardiography performed before pacemaker implantation and at the end of follow‐up were collected. The patients in the RVOT septal pacing and RVAP groups showed similar demographic and clinical characteristics before pacing treatments. After a mean follow‐up of 2 years, the final maximum P‐wave duration; P‐wave dispersion; Q‐, R‐, and S‐wave complex duration; left atrial volume index; left ventricular end‐systolic diameter; ratio of transmitral early diastolic filling velocity to mitral annular early diastolic velocity; and interventricular mechanical delay in the RVOT septal pacing group were significantly less than those in the RVAP group (P<0.05). The final left ventricular ejection fraction of the RVOT septal pacing group was significantly higher than that of the RVAP group (P<0.05). Conclusions Compared with RVAP, RVOT septal pacing has fewer adverse effects regarding atrial electrical activity and structure in patients with normal cardiac function. PMID:25896891

Ischemic Ventricular Tachycardia Presenting as a Narrow Complex Tachycardia

PubMed Central

Page, Stephen P; Watts, Troy; Yeo, Wee Tiong; Mehul, Dhinoja

2014-01-01

This report describes a patient presenting with a narrow complex tachycardia in the context of prior myocardial infarction and impaired ventricular function. Electrophysiological studies confirmed ventricular tachycardia and activation and entrainment mapping demonstrated a critical isthmus within an area of scar involving the His-Purkinje system accounting for the narrow QRS morphology. This very rare case shares some similarities with upper septal ventricular tachycardia seen in patients with structurally normal hearts, but to our knowledge has not been seen previously in patients with ischemic heart disease. PMID:25057222

Tricuspid regurgitation and right ventricular function after mitral valve surgery with or without concomitant tricuspid valve procedure.

PubMed

Desai, Ravi R; Vargas Abello, Lina Maria; Klein, Allan L; Marwick, Thomas H; Krasuski, Richard A; Ye, Ying; Nowicki, Edward R; Rajeswaran, Jeevanantham; Blackstone, Eugene H; Pettersson, Gösta B

2013-11-01

To study the effect of mitral valve repair with or without concomitant tricuspid valve repair on functional tricuspid regurgitation and right ventricular function. From 2001 to 2007, 1833 patients with degenerative mitral valve disease, a structurally normal tricuspid valve, and no coronary artery disease underwent mitral valve repair, and 67 underwent concomitant tricuspid valve repair. Right ventricular function (myocardial performance index and tricuspid annular plane systolic excursion) was measured before and after surgery using transthoracic echocardiography for randomly selected patients with tricuspid regurgitation grade 0, 1+, and 2+ (100 patients for each grade) and 93 with grade 3+/4+, 393 patients in total. In patients with mild (<3+) preoperative tricuspid regurgitation, mitral valve repair alone was associated with reduced tricuspid regurgitation and mild worsening of right ventricular function. Tricuspid regurgitation of 2+ or greater developed in fewer than 20%, and right ventricular function had improved, but not to preoperative levels, at 3 years. In patients with severe (3+/4+) preoperative tricuspid regurgitation, mitral valve repair alone reduced tricuspid regurgitation and improved right ventricular function; however, tricuspid regurgitation of 2+ or greater returned and right ventricular function worsened toward preoperative levels within 3 years. Concomitant tricuspid valve repair effectively eliminated severe tricuspid regurgitation and improved right ventricular function. Also, over time, tricuspid regurgitation did not return and right ventricular function continued to improve to levels comparable to that of patients with lower grades of preoperative tricuspid regurgitation. In patients with mitral valve disease and severe tricuspid regurgitation, mitral valve repair alone was associated with improved tricuspid regurgitation and right ventricular function. However, the improvements were incomplete and temporary. In contrast, concomitant tricuspid valve repair effectively and durably eliminated severe tricuspid regurgitation and improved right ventricular function toward normal, supporting an aggressive approach to important functional tricuspid regurgitation. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Tricuspid regurgitation and right ventricular function after mitral valve surgery with or without concomitant tricuspid valve procedure

PubMed Central

Desai, Ravi R.; Vargas Abello, Lina Maria; Klein, Allan L.; Marwick, Thomas H.; Krasuski, Richard A.; Ye, Ying; Nowicki, Edward R.; Rajeswaran, Jeevanantham; Blackstone, Eugene H.; Pettersson, Gösta B.

2014-01-01

Objectives To study the effect of mitral valve repair with or without concomitant tricuspid valve repair on functional tricuspid regurgitation and right ventricular function. Methods From 2001 to 2007, 1833 patients with degenerative mitral valve disease, a structurally normal tricuspid valve, and no coronary artery disease underwent mitral valve repair, and 67 underwent concomitant tricuspid valve repair. Right ventricular function (myocardial performance index and tricuspid annular plane systolic excursion) was measured before and after surgery using transthoracic echocardiography for randomly selected patients with tricuspid regurgitation grade 0, 1+, and 2+(100 patients for each grade) and 93 with grade 3+/4+, 393 patients in total. Results In patients with mild (<3+) preoperative tricuspid regurgitation, mitral valve repair alone was associated with reduced tricuspid regurgitation and mild worsening of right ventricular function. Tricuspid regurgitation of 2+or greater developed in fewer than 20%, and right ventricular function had improved, but not to preoperative levels, at 3 years. In patients with severe (3+/4+) preoperative tricuspid regurgitation, mitral valve repair alone reduced tricuspid regurgitation and improved right ventricular function; however, tricuspid regurgitation of 2+ or greater returned and right ventricular function worsened toward preoperative levels within 3 years. Concomitant tricuspid valve repair effectively eliminated severe tricuspid regurgitation and improved right ventricular function. Also, over time, tricuspid regurgitation did not return and right ventricular function continued to improve to levels comparable to that of patients with lower grades of preoperative tricuspid regurgitation. Conclusions In patients with mitral valve disease and severe tricuspid regurgitation, mitral valve repair alone was associated with improved tricuspid regurgitation and right ventricular function. However, the improvements were incomplete and temporary. In contrast, concomitant tricuspid valve repair effectively and durably eliminated severe tricuspid regurgitation and improved right ventricular function toward normal, supporting an aggressive approach to important functional tricuspid regurgitation. PMID:23010580

Papillary Muscle Repositioning as a Subvalvular Apparatus Preservation Technique in Mitral Stenosis Patients with Normal Left Ventricular Systolic Function

PubMed Central

Lafci, Gokhan; Cagli, Kerim; Korkmaz, Kemal; Turak, Osman; Uzun, Alper; Yalcinkaya, Adnan; Diken, Adem; Gunertem, Eren; Cagli, Kumral

2014-01-01

Subvalvular apparatus preservation is an important concept in mitral valve replacement (MVR) surgery that is performed to remedy mitral regurgitation. In this study, we sought to determine the effects of papillary muscle repositioning (PMR) on clinical outcomes and echocardiographic left ventricular function in rheumatic mitral stenosis patients who had normal left ventricular systolic function. We prospectively assigned 115 patients who were scheduled for MVR surgery with mechanical prosthesis to either PMR or MVR-only groups. Functional class and echocardiographic variables were evaluated at baseline and at early and late postoperative follow-up examinations. All values were compared between the 2 groups. The PMR group consisted of 48 patients and the MVR-only group of 67 patients. The 2 groups’ baseline characteristics and surgery-related factors (including perioperative mortality) were similar. During the 18-month follow-up, all echocardiographic variables showed a consistent improvement in the PMR group; the mean left ventricular ejection fraction deteriorated significantly in the MVR-only group. Comparison during follow-up of the magnitude of longitudinal changes revealed that decreases in left ventricular end-diastolic and end-systolic diameters and in left ventricular sphericity indices, and increases in left ventricular ejection fractions, were significantly higher in the PMR group than in the MVR-only group. This study suggests that, in patients with rheumatic mitral stenosis and preserved left ventricular systolic function, the addition of papillary muscle repositioning to valve replacement with a mechanical prosthesis improves left ventricular dimensions, ejection fraction, and sphericity index at the 18-month follow-up with no substantial undesirable effect on the surgery-related factors. PMID:24512397

Added value of cardiac magnetic resonance in etiological diagnosis of ventricular arrhythmias.

PubMed

Cabanelas, Nuno; Vidigal Ferreira, Maria João; Donato, Paulo; Gaspar, António; Pinto, Joana; Caseiro-Alves, Filipe; Providência, Luís Augusto

2013-10-01

Cardiac magnetic resonance (CMR) imaging is increasingly important in the diagnostic work-up of a wide range of heart diseases, including those with arrhythmogenic potential. To assess the added value of CMR in etiological diagnosis of ventricular arrhythmias after an inconclusive conventional investigation. Patients undergoing CMR between 2005 and 2011 for investigation of ventricular arrhythmias were included (n=113). All had documented arrhythmias. Those with a definite diagnosis from a previous investigation and those with evidence of coronary artery disease (acute coronary syndrome, typical angina symptoms, increase in biomarkers or positive stress test) were excluded. CMR results were considered relevant when they fulfilled diagnostic criteria. Of the 113 patients, 57.5% were male and mean age was 41.7 ± 16.2 years. Regarding the initial arrhythmia, 38.1% had ventricular fibrillation/sustained ventricular tachycardia (VF/VT) and 61.9% had less complex ventricular ectopy. CMR imaging showed criteria of a specific diagnosis in 42.5% of patients, was totally normal in 36.3%, and showed non-specific alterations in the remainder. In VF/VT patients, specific criteria were found in 60.4%, and in 31.4% of those with less complex ectopy. The most frequent diagnoses were arrhythmogenic right ventricular dysplasia, ventricular non-compaction and myopericarditis. It is worth noting that, although there was no evidence of previous coronary artery disease, 6.2% of patients had a late gadolinium enhancement distribution pattern compatible with myocardial infarction. CMR gives additional and important information in the diagnostic work-up of ventricular arrhythmias after an inconclusive initial investigation. The proportion of patients with diagnostic criteria was 42.5% (60.0% in those with VF/VT), and CMR was completely normal in 36.6%. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

Growth of left ventricular mass with military basic training in army recruits.

PubMed

Batterham, Alan M; George, Keith P; Birch, Karen M; Pennell, Dudley J; Myerson, Saul G

2011-07-01

Exercise-induced left ventricular hypertrophy is well documented, but whether this occurs merely in line with concomitant increases in lean body mass is unclear. Our aim was to model the extent of left ventricular hypertrophy associated with increased lean body mass attributable to an exercise training program. Cardiac and whole-body magnetic resonance imaging was performed before and after a 10-wk intensive British Army basic training program in a sample of 116 healthy Caucasian males (aged 17-28 yr). The within-subjects repeated-measures allometric relationship between lean body mass and left ventricular mass was modeled to allow the proper normalization of changes in left ventricular mass for attendant changes in lean body mass. To linearize the general allometric model (Y=aXb), data were log-transformed before analysis; the resulting effects were therefore expressed as percent changes. We quantified the probability that the true population increase in normalized left ventricular mass was greater than a predefined minimum important difference of 0.2 SD, assigning a probabilistic descriptive anchor for magnitude-based inference. The absolute increase in left ventricular mass was 4.8% (90% confidence interval=3.5%-6%), whereas lean body mass increased by 2.6% (2.1%-3.0%). The change in left ventricular mass adjusted for the change in lean body mass was 3.5% (1.9%-5.1%), equivalent to an increase of 0.25 SD (0.14-0.37). The probability that this effect size was greater than or equal to our predefined minimum important change of 0.2 SD was 0.78-likely to be important. After correction for allometric growth rates, left ventricular hypertrophy and lean body mass changes do not occur at the same magnitude in response to chronic exercise.

Long-term results after left ventricular aneurysmectomy.

PubMed Central

Otterstad, J E; Christensen, O; Levorstad, K; Nitter-Hauge, S

1981-01-01

Twenty-six patients (21 men and five women) with a mean age of 54.8 years have been reinvestigated nine to 62 months (mean 29.7) after left ventricular aneurysmectomy. Preoperatively left ventricular angiography disclosed an anterior aneurysm in all cases, which was large in 15 (57%) and small to medium in 11 (42%). At follow-up a large residual aneurysm was found in five (19%), a small to medium one in 13 (50%), and akinesia without aneurysm in eight (31%). The sum of ST elevation (sigma ST) in praecordial leads in the electrocardiogram was reduced from a mean value of 11.2 mm to 7.7 mm. In no patient did ST segments return to normal after operation. Preoperatively, mean sigma ST was identical in patients with large and with small to medium aneurysms. At reinvestigation mean sigma ST was identical in patients with large and with small to medium residual aneurysms as well as in patients with akinesia. Left ventricular end-diastolic pressure before angiography was reduced from a mean value of 21.5 mm to 15.1 mmHg and after angiography from 26.7 mm to 21.1 mmHg. Progression of coronary artery stenoses was a characteristic finding in patients whose left ventricular end-diastolic pressures did not return to normal. These patients had a longer follow-up time than those with no progression of coronary disease, who all showed an improvement in left ventricular end-diastolic pressure. Six patients who had coronary bypass grafting performed had unchanged left ventricular end-diastolic pressures at follow-up. The results indicate that progression of coronary artery disease may be responsible for an eventual further deterioration in left ventricular function after aneurysmectomy. Additional bypass grafting did not result in improved left ventricular function. PMID:6971647

Biomechanics of Cardiac Function

PubMed Central

Voorhees, Andrew P.; Han, Hai-Chao

2015-01-01

The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments. PMID:26426462

Characteristics of single Ca(2+) channel kinetics in feline hypertrophied ventricular myocytes.

PubMed

Yang, Xiangjun; Hui, Jie; Jiang, Tingbo; Song, Jianping; Liu, Zhihua; Jiang, Wenping

2002-04-01

To explore the mechanism underlying the prolongation of action potential and delayed inactivation of the L-type Ca(2+) (I(Ca, L)) current in a feline model of left ventricular system hypertension and concomitant hypertrophy. Single Ca(2+) channel properties in myocytes isolated from normal and pressure overloaded cat left ventricles were studied, using patch-clamp techniques. Left ventricular pressure overload was induced by partial ligation of the ascending aorta for 4 - 6 weeks. The amplitude of single Ca(2+) channel current evoked by depolarizing pulses from -40 mV to 0 mV was 1.02 +/- 0.03 pA in normal cells and 1.05 +/- 0.03 pA in hypertrophied cells, and there was no difference in single channel current-voltage relationships between the groups since slope conductance was 26.2 +/- 1.0 pS in normal and hypertrophied cells, respectively. Peak amplitudes of the ensemble-averaged single Ca(2+) channel currents were not different between the two groups of cells. However, the amplitude of this averaged current at the end of the clamp pulse was significantly larger in hypertrophied cells than in normal cells. Open-time histograms revealed that open-time distribution was fitted by a single exponential function in channels of normal cells and by a two exponential function in channels of hypertrophied cells. The number of long-lasting openings was increased in channels of hypertrophied cells, and therefore the calculated mean open time of the channel was significantly longer compared to normal controls. Kinetic changes in the Ca(2+) channel may underlie both hypertrophy-associated delayed inactivation of the Ca(2+) current and, in part, the pressure overload-induced action potential lengthening in this cat model of ventricular left systolic hypertension and hypertrophy.

Effects of increased left ventricular wall thickness on the myocardium in severe aortic stenosis with normal left ventricular ejection fraction: Two- and three-dimensional multilayer speckle tracking echocardiography.

PubMed

Cho, Eun Jeong; Park, Sung-Ji; Kim, Eun Kyoung; Lee, Ga Yeon; Chang, Sung-A; Choi, Jin-Oh; Lee, Sang-Chol; Park, Seung Woo

2017-04-01

The aim of this study was to determine the capability of real time three-dimensional echocardiography (RT3DE) and two-dimensional (2D) multilayer speckle tracking echocardiography (MSTE) for evaluation of early myocardial dysfunction triggered by increased left ventricular (LV) wall thickness in severe aortic stenosis (AS) with normal LV ejection fraction (EF≥55%). Conventional, RT3D STE and 2D MSTE were performed in 45 patients (mean 68.9±9.0 years) with severe AS (aortic valve area <1 cm 2 , aortic velocity Vmax >4 m/s or mean PG >40 mm Hg) and normal left ventricular ejection fraction (LVEF) without overt coronary artery disease and in 18 age-, sex-matched healthy controls. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS), and global radial strain (GRS) were calculated using RT3DE and MSTE. The severe AS group had lower 3D GLS, GRS, GAS and 2D epicardium, and mid-wall and endocardium GLS compared to healthy controls. In MSTE analysis, 2D LS and CS values decreased from the endocardial layer toward the epicardial layer. Severe AS patients with increased LV wall thickness had lower 3D GLS and 2D epicardium, and mid-wall and endocardium GLS compared with severe AS patients without LV wall thickening. GLS on RT3D STE was correlated with GLS on 2D MSTE, left ventricular mass index, LVEF, left atrial volume index, and lnNT-proBNP. RT3DE and 2D MSTE can be used to identify subtle contractile dysfunction triggered by increased LV wall thickness in severe AS with normal LVEF. Therefore, RT3D STE and 2D MSTE may provide additional information that can facilitate decision-making regarding severe AS patients with increased LV wall thickness and normal LV function. © 2017, Wiley Periodicals, Inc.

Persistent recovery of normal left ventricular function and dimension in idiopathic dilated cardiomyopathy during long‐term follow‐up: does real healing exist?

PubMed

Merlo, Marco; Stolfo, Davide; Anzini, Marco; Negri, Francesco; Pinamonti, Bruno; Barbati, Giulia; Ramani, Federica; Lenarda, Andrea Di; Sinagra, Gianfranco

2015-01-13

An important number of patients with idiopathic dilated cardiomyopathy have dramatically improved left ventricular function with optimal treatment; however, little is known about the evolution and long-term outcome of this subgroup, which shows apparent healing. This study assesses whether real healing actually exists in dilated cardiomyopathy. Persistent apparent healing was evaluated among 408 patients with dilated cardiomyopathy receiving tailored medical treatment and followed over the very long-term. Persistent apparent healing was defined as left ventricular ejection fraction ≥50% and indexed left ventricular end-diastolic diameter ≤33 mm/m(2) at both mid-term (19±4 months) and long-term (103±9 months) follow-up. At mid-term, 63 of 408 patients (15%) were apparently healed; 38 (60%; 9%of the whole population) showed persistent apparent healing at long-term evaluation. No predictors of persistent apparent healing were found. Patients with persistent apparent healing showed better heart transplant–free survival at very long-term follow-up (95% versus 71%; P=0.014) compared with nonpersistently normalized patients. Nevertheless, in the very longterm, 37% of this subgroup experienced deterioration of left ventricular systolic function, and 5% died or had heart transplantation. Persistent long-term apparent healing was evident in a remarkable proportion of dilated cardiomyopathy patients receiving optimal medical treatment and was associated with stable normalization of main clinical and laboratory features. This condition can be characterized by a decline of left ventricular function over the very long term, highlighting the relevance of serial nd individualized follow-up in all patients with dilated cardiomyopathy, especially considering the absence of predictors for longterm apparent healing.

Global Bi-ventricular endocardial distribution of activation rate during long duration ventricular fibrillation in normal and heart failure canines.

PubMed

Luo, Qingzhi; Jin, Qi; Zhang, Ning; Han, Yanxin; Wang, Yilong; Huang, Shangwei; Lin, Changjian; Ling, Tianyou; Chen, Kang; Pan, Wenqi; Wu, Liqun

2017-04-13

The objective of this study was to detect differences in the distribution of the left and right ventricle (LV & RV) activation rate (AR) during short-duration ventricular fibrillation (SDVF, <1 min) and long-duration ventricular fibrillation VF (LDVF, >1 min) in normal and heart failure (HF) canine hearts. Ventricular fibrillation (VF) was electrically induced in six healthy dogs (control group) and six dogs with right ventricular pacing-induced congestive HF (HF group). Two 64-electrode basket catheters deployed in the LV and RV were used for global endocardium electrical mapping. The AR of VF was estimated by fast Fourier transform analysis from each electrode. In the control group, the LV was activated faster than the RV in the first 20 s, after which there was no detectable difference in the AR between them. When analyzing the distribution of the AR within the bi-ventricles at 3 min of LDVF, the posterior LV was activated fastest, while the anterior was slowest. In the HF group, a detectable AR gradient existed between the two ventricles within 3 min of VF, with the LV activating more quickly than the RV. When analyzing the distribution of the AR within the bi-ventricles at 3 min of LDVF, the septum of the LV was activated fastest, while the anterior was activated slowest. A global bi-ventricular endocardial AR gradient existed within the first 20 s of VF but disappeared in the LDVF in healthy hearts. However, the AR gradient was always observed in both SDVF and LDVF in HF hearts. The findings of this study suggest that LDVF in HF hearts can be maintained differently from normal hearts, which accordingly should lead to the development of different management strategies for LDVF resuscitation.

Normal reference ranges for left ventricular dimensions in preterm infants.

PubMed

Abushaban, Lulu; Vel, Mariappa Thinakar; Rathinasamy, Jebaraj; Sharma, Prem N

2014-09-01

To establish normal reference ranges for the left ventricular dimensions in preterm infants and their correlation with gestational age, body weight and chronological age. In a prospective study, 268 preterm babies, who fulfilled the criteria for inclusion, were examined in Kuwait during the years (2008-2010). Echocardiograms were performed to measure the left ventricular dimensions on 0-6 day(s) of life and at weekly intervals until they reached 36 weeks. The gestational age was grouped into three: 24-27, 28-31 and 32-35 weeks, and body weight into five: ⩽999, 1,000-1,499, 1,500-1,999, 2,000-2,499 and ≥2,500 grams. The overall group differences were compared for each period of life: 0-6 days, 1-2, 3-4 and ≥5 weeks. The mean gestational age was 29.8 (± 2.38 SD) weeks, ranging between 24 and 35, and the mean body weight 1,479 (± 413 SD) grams, ranging between 588 and 3380. At the first scan (0-6 days of life), all the left ventricular measurements correlated well (P < 0.001) with body weight, and the same was observed with gestational age, except for left ventricular posterior wall thickness at end-systole and end-diastole. A significant gradual increase was noticed in all the dimensions with body weight during each period of life. However, with respect to gestational age, an increase was observed in all the dimensions during first four weeks, but the rate of increase became less after 5 weeks of life. Overall, a progressive and significant increase in all left ventricle measurements was observed during the first nine weeks of life. The left ventricular dimension measurements were found to have significant correlation with both gestational age and body weight. The study also provides reference data, which can be used as normal reference tool for left ventricular dimensions for preterm infants against the gestational age, body weight and chronological age.

The effect of captopril and losartan on the electrophysiology of myocardial cells of myocardial ischemia rats.

PubMed

Shi, Xiangmin; Shan, Zhaoling; Yuan, Hongtao; Guo, Hongyang; Wang, Yutang

2014-01-01

This study aims to investigate the effect of captopril and losartan on the electrophysiology of myocardial cells parameters in ventricular vulnerable period and effective refractory period of myocardial ischemia rats. 96 wistar rats were enrolled in the study and divided into six groups: Captopril myocardial ischemia group, losartan myocardial ischemia group, myocardial ischemia control group, captopril normal group, losartan normal group and normal control group (n=16). We observed morphological changes of myocardial tissue in each group. The cardiac electrophysiological parameters in effective refractory period of each group were measured. Creatine kinase (CK), alanine aminotransferase (GOT), lactate dehydrogenase (LDH), the expression of Cardiotrophin 1 (CT-1) and malonaldehyde (MDA) were detected. Compared the losartan and captopril group with the control group, (P<0.05). Losartan and captopril can shorten the ventricular vulnerable period of the normal group and ischemic group. There was no interaction effect between losartan and captopril group and the acute myocardial ischemia group. The effect of losartan and captopril on time window in ventricular vulnerable period showed that compared with the control group (P<0.05). Losartan and captopril had a significant effect on prolonged effective refractory period of normal and ischemic rats. There was no interaction effect between losartan and captopril group and the acute myocardial ischemia group. Compared with the myocardial ischemia control group, CK, GOT, LDH and MDA decreased in captopril and losartan myocardial ischemia groups (P<0.05). Losartan and captopril had a significant effect on prolonged effective refractory period and shorten ventricular vulnerable period, they can also effectively prevent arrhythmias.

[The effect of atrial pacing on left ventricular diastolic function and BNP levels in patients with DDD pacemaker].

PubMed

Apali, Zeynep; Bayata, Serdar; Yeşil, Murat; Arikan, Erdinç; Postaci, Nursen

2010-08-01

We aimed to investigate the effect of atrial pacing on left ventricular diastolic function and brain natriuretic peptide (BNP) levels in patients with DDD pacemaker. Thirty patients with complete atrio-ventricular (AV) block and DDD pacemaker were included. All patients had normal left ventricular systolic function. Echocardiographic diastolic function parameters (transmitral and tissue Doppler velocities during early (E and E') and late (A and A') filling) and NT-pro-BNP levels were evaluated prospectively during atrial sensing and pacing periods. Echocardiographic data were compared with paired sample t test and NT-pro-BNP levels were compared with Wilcoxon test. Echocardiographic E/A, E'/A', E/E' ratios were calculated as 0.72+/-0.34, 0.61+/-0.21 and 8.76+/-2.58 during atrial sensing period. Same parameters were found as 0.71+/-0.23, 0.64+/-0.16 and 8.93+/-3.16 respectively during atrial pacing period. Echocardiographic left ventricular diastolic function parameters were not significantly different during atrial pacing and atrial sensing periods. Median plasma NT-pro-BNP levels were measured as 142 pg/ml (min-max 47-563 pg/ml) and 147 pg/ml (min-max 33-1035 pg/ml) during atrial sensing and pacing periods respectively. These levels were not significantly different (p=0.86). The result of this study has shown that, atrial pacing has not any additional detrimental effect on left ventricular diastolic function parameters in paced patients with normal left ventricular systolic function.

Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.

PubMed

Fan, Ling; Chen, Li-Feng; Fan, Jing

2017-12-01

To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure. Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet, pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency. Compared with the control group, 4 phase automatic depolarization velocity, spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly (P < 0.01) and action potential amplitude reduced (P < 0.01) in model group. Moreover, repolarization 50% and 90% increased (P < 0.01). There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Dilated cardiomyopathy with short QT interval: is it a new clinical entity?

PubMed

Bohora, Shomu; Namboodiri, Narayanan; Tharakan, Jaganmohan; Vk, Ajit Kumara; Nayyar, Sachin

2009-05-01

Short QT syndrome is a rare autosomal dominant channelopathy of structurally normal hearts characterized by atrial fibrillation, ventricular arrhythmias, and sudden cardiac death. We report a case having short QT, dilated ventricles, and severe ventricular dysfunction, an unreported association so far.

Myocardial perfusion and left ventricular function indices assessed by gated myocardial perfusion SPECT in methamphetamine abusers.

PubMed

Dadpour, Bita; Dabbagh Kakhki, Vahid R; Afshari, Reza; Dorri-Giv, Masoumeh; Mohajeri, Seyed A R; Ghahremani, Somayeh

2016-12-01

Methamphetamine (MA) is associated with alterations of cardiac structure and function, although it is less known. In this study, we assessed possible abnormality in myocardial perfusion and left ventricular function using gated myocardial perfusion SPECT. Fifteen patients with MA abuse, on the basis of Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) MA dependency determined by Structured Clinical Interview for DSM-IV, underwent 2-day dipyridamole stress/rest Tc-sestamibi gated myocardial perfusion SPECT. An average daily dose of MA use was 0.91±1.1 (0.2-4) g. The duration of MA use was 3.4±2.1 (1-7) years. In visual and semiquantitative analyses, all patients had normal gated myocardial perfusion SPECT, with no perfusion defects. In all gated SPECT images, there was no abnormality in left ventricular wall motion and thickening. All summed stress scores and summed rest scores were below 3. Calculated left ventricular functional indices including the end-diastolic volume, end-systolic volume, and left ventricular ejection fraction were normal. Many cardiac findings because of MA mentioned in previous reports are less likely because of significant epicardial coronary artery stenosis.

Factors related to outcome in heart failure with a preserved (or normal) left ventricular ejection fraction.

PubMed

Sanderson, John E

2016-07-01

Heart failure with a preserved ejection faction (HFpEF) is a growing and expensive cause of heart failure (HF) affecting particularly the elderly. It differs in substantial ways in addition to the normal left ventricular ejection fraction, from the more easily recognized form of heart failure with a reduced ejection fraction (HFrEF or 'systolic heart failure') and unlike HFrEF there have been little advances in treatment. In part, this relates to the complexity of the pathophysiology and identifying the correct targets. In HFpEF, there appears to be widespread stiffening of the vasculature and the myocardium affecting ventricular function (both systolic and diastolic), impeding ventricular suction, and thus early diastolic filling leading to breathlessness on exertion and later atrial failure and fibrillation. Left ventricular ejection fraction tends to gradually decline and some evolve into HFrEF. Most patients also have a mixture of several co-morbidities including hypertension, diabetes, obesity, poor renal function, lack of fitness, and often poor social conditions. Therefore, many factors may influence outcome in an individual patient. In this review, the epidemiology, possible causation, pathophysiology, the influence of co-morbidities and some of the many potential predictors of outcome will be considered.

Lacosamide-Induced Recurrent Ventricular Tachycardia in the Acute Care Setting.

PubMed

Berei, Theodore J; Lillyblad, Matthew P; Almquist, Adrian K

2018-04-01

Lacosamide is a new-generation antiepileptic drug (AED) most commonly used adjunctively in the setting of partial-onset seizures refractory to traditional therapy. We describe the first case report, to our knowledge, of a patient who developed recurrent, sustained ventricular tachycardia with multiple administrations of lacosamide in an acute setting. A 70-year-old woman with a history significant for valvular heart disease was admitted to the inpatient cardiology service for worsening heart failure. On hospital day 7, she received a bioprosthetic aortic valve. Prior to surgery and immediately after, the patient's electrocardiogram (ECG) was normal. After developing multiple generalized tonic-clonic seizures refractory to levetiracetam, fosphenytoin, and valproic acid, the decision was made to initiate lacosamide. Two hours following the second lacosamide dose, the patient developed a wide complex QRS that transitioned into sustained ventricular tachycardia requiring electrical cardioversion. Sustained ventricular tachycardia occurred again, just hours after the third dose of lacosamide was given. Following cessation of lacosamide, the patient's QRS interval normalized and has since had no documented episodes of ventricular tachycardia. Clinicians should be aware of the potential for life-threatening rhythmic disturbances in patients initiated on lacosamide and the need for vigilant ECG, electrolyte, and drug-drug monitoring.

Clinical determinants and consequences of left ventricular hypertrophy.

PubMed

Messerli, F H

1983-09-26

The left ventricle adapts to an increased afterload such as that produced by arterial hypertension with concentric left ventricular hypertrophy. However, this adaptive process can be modified by a variety of physiologic and pathophysiologic states. Progressive aging, black race, and perhaps disorders with an increased sympathetic outflow seem to accelerate left ventricular hypertrophy. Obesity and other high cardiac output states predominantly produce dilatation of the left ventricle, and their combination with arterial hypertension results in eccentric left ventricular hypertrophy. Similarly, endurance exercise increases left ventricular volume more than wall thickness, whereas isometric exercise produces an increase in wall thickness only. The presence or absence of some physiologic and pathogenetic factors has direct implication on the assessment of what constitutes a "normal" left ventricular structure and function. Left ventricular hypertrophy has been shown to increase ventricular ectopic impulse generation and to put patients at a high risk of sudden death. Moreover, the increase in myocardial mass lowers coronary reserve and enhances cardiac oxygen requirements. Thus, the presence of left ventricular hypertrophy has to be considered as an ominous sign rather than as a benign adaptive process.

First report of atretic coronary sinus stenting in a 5-kg infant resulting in dramatic improvement of ventricular function in functional single ventricle.

PubMed

El-Said, Howaida; Hegde, Sanjeet; Moore, John

2014-01-01

The patient was a male infant with L-transposition of great arteries (L-TGA), Ebstein's anomaly of the tricuspid valve, subvalvar aortic stenosis, ventricular septal defect (VSD), hypoplastic right ventricle, arch hypoplasia, and congenital complete heart block. He underwent a Norwood procedure, aortic arch repair, permanent pacemaker implantation, and a 3.5-mm aortopulmonary shunt at 4 days of age. At the time of his surgery, left ventricular function was in the normal range (ejection fraction [EF] = 67%). However by 3 months of age, he was noted to have developed moderate-severe biventricular dysfunction (left ventricular ejection fraction [LVEF] = 34%). Atresia of the coronary sinus with a small left superior venacava (LSVC) and a bridging vein was discovered during cardiac catheterization at this time. The coronary sinus mean pressure was 17 mm Hg, and the common atrial mean pressure was 6 mmHg. We opened the atretic coronary sinus ostium using radiofrequency ablation and stent placement. There was dramatic improvement in ventricular function observed over a 2-month period. Follow-up cardiac catheterization 5 months later revealed the stent in the coronary sinus to be widely patent with no intimal buildup, and the ventricular function was normal (LVEF = 58%). The patient had a bidirectional Glenn procedure with an uncomplicated postoperative course and is currently awaiting Fontan completion. © 2013 Wiley Periodicals, Inc.

[Arrhythmogenic right ventricular cardiomyopathy. Case report and a brief literature review].

PubMed

Izurieta, Carlos; Curotto-Grasiosi, Jorge; Rocchinotti, Mónica; Torres, María J; Moranchel, Manuel; Cañas, Sebastián; Cardús, Marta E; Alasia, Diego; Cordero, Diego J; Angel, Adriana

2013-01-01

A 51-year-old man was admitted to this hospital because of palpitations and a feeling of dizziness for a period of 2h. The electrocardiogram revealed a regular wide-QRS complex tachycardia at a rate of 250 beats per minute, with superior axis and left bundle branch block morphology without hemodynamically decompensation, the patient was cardioverted to sinus rhythm after the administration of a loading and maintenance dose of amiodarone. The elechtrophysiological study showed the ventricular origin of the arrhythmia. In order to diagnose the etiology of the ventricular tachycardia we performed a coronary arteriography that showed normal epicardial vessels, thus ruling out coronary disease. Doppler echocardiography revealed systolic and diastolic functions of both left and right ventricles within normal parameters, and normal diameters as well. A cardiac magnetic resonance with late enhancement was done, showing structural abnormalities of the right ventricle wall with moderate impairment of the ejection fraction, and a mild dysfunction of the left ventricle. The diagnosis of arrhythmogenic right ventricular cardiomyopathy was performed as 2 major Task Force criteria were met. We implanted an automatic cardioverter defibrillator as a prophylactic measure. The patient was discharged without complications. Copyright © 2012 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Association between left ventricular dysfunction, anemia, and chronic renal failure. Analysis of the Heart Failure Prevalence and Predictors in Turkey (HAPPY) cohort.

PubMed

Kepez, A; Mutlu, B; Degertekin, M; Erol, C

2015-06-01

Anemia and chronic renal failure (CRF) are frequent comorbidities in patients with heart failure (HF), and they have been reported to be associated with increased mortality and hospitalization rates. HF, anemia, and CRF have been reported to interact with each other forming a vicious cycle termed cardio-renal-anemia syndrome. The aim of the present study was to evaluate the association of HF, anemia, and CRF using data from the large-scale"Heart Failure Prevalence and Predictors in Turkey (HAPPY)" study. Among the HAPPY cohort, 3,369 subjects who had either left ventricular dysfunction (LVD) or normal left ventricular function on echocardiography or normal serum NT-proBNP levels were included in this analysis. The prevalence of anemia and CRF was significantly higher in patients with LVD compared with subjects with normal ventricular function (20.7 % vs. 4.0 % and 19.0 % vs. 3.7 %, respectively; p < 0.001 for each). Binary logistic regression analyses for the presence of LVD, anemia, and CRF demonstrated that each one was an independent predictor for the presence of the others. These findings point to the presence of cardio-renal-anemia syndrome and the necessity of treating these comorbidities in patients with HF.

Accurate means of detecting and characterizing abnormal patterns of ventricular activation by phase image analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Botvinick, E.H.; Frais, M.A.; Shosa, D.W.

1982-08-01

The ability of scintigraphic phase image analysis to characterize patterns of abnormal ventricular activation was investigated. The pattern of phase distribution and sequential phase changes over both right and left ventricular regions of interest were evaluated in 16 patients with normal electrical activation and wall motion and compared with those in 8 patients with an artificial pacemaker and 4 patients with sinus rhythm with the Wolff-Parkinson-White syndrome and delta waves. Normally, the site of earliest phase angle was seen at the base of the interventricular septum, with sequential change affecting the body of the septum and the cardiac apex andmore » then spreading laterally to involve the body of both ventricles. The site of earliest phase angle was located at the apex of the right ventricle in seven patients with a right ventricular endocardial pacemaker and on the lateral left ventricular wall in one patient with a left ventricular epicardial pacemaker. In each case the site corresponded exactly to the position of the pacing electrode as seen on posteroanterior and left lateral chest X-ray films, and sequential phase changes spread from the initial focus to affect both ventricles. In each of the patients with the Wolff-Parkinson-White syndrome, the site of earliest ventricular phase angle was located, and it corresponded exactly to the site of the bypass tract as determined by endocardial mapping. In this way, four bypass pathways, two posterior left paraseptal, one left lateral and one right lateral, were correctly localized scintigraphically. On the basis of the sequence of mechanical contraction, phase image analysis provides an accurate noninvasive method of detecting abnormal foci of ventricular activation.« less

The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

PubMed

Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

2016-02-01

Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output. © 2016. Published by The Company of Biologists Ltd.

Timing of myocardial trpm7 deletion during cardiogenesis variably disrupts adult ventricular function, conduction, and repolarization.

PubMed

Sah, Rajan; Mesirca, Pietro; Mason, Xenos; Gibson, William; Bates-Withers, Christopher; Van den Boogert, Marjolein; Chaudhuri, Dipayan; Pu, William T; Mangoni, Matteo E; Clapham, David E

2013-07-09

Transient receptor potential (TRP) channels are a superfamily of broadly expressed ion channels with diverse physiological roles. TRPC1, TRPC3, and TRPC6 are believed to contribute to cardiac hypertrophy in mouse models. Human mutations in TRPM4 have been linked to progressive familial heart block. TRPM7 is a divalent-permeant channel and kinase of unknown function, recently implicated in the pathogenesis of atrial fibrillation; however, its function in ventricular myocardium remains unexplored. We generated multiple cardiac-targeted knockout mice to test the hypothesis that TRPM7 is required for normal ventricular function. Early cardiac Trpm7 deletion (before embryonic day 9; TnT/Isl1-Cre) results in congestive heart failure and death by embryonic day 11.5 as a result of hypoproliferation of the compact myocardium. Remarkably, Trpm7 deletion late in cardiogenesis (about embryonic day 13; αMHC-Cre) produces viable mice with normal adult ventricular size, function, and myocardial transcriptional profile. Trpm7 deletion at an intermediate time point results in 50% of mice developing cardiomyopathy associated with heart block, impaired repolarization, and ventricular arrhythmias. Microarray analysis reveals elevations in transcripts of hypertrophy/remodeling genes and reductions in genes important for suppressing hypertrophy (Hdac9) and for ventricular repolarization (Kcnd2) and conduction (Hcn4). These transcriptional changes are accompanied by action potential prolongation and reductions in transient outward current (Ito; Kcnd2). Similarly, the pacemaker current (If; Hcn4) is suppressed in atrioventricular nodal cells, accounting for the observed heart block. Trpm7 is dispensable in adult ventricular myocardium under basal conditions but is critical for myocardial proliferation during early cardiogenesis. Loss of Trpm7 at an intermediate developmental time point alters the myocardial transcriptional profile in adulthood, impairing ventricular function, conduction, and repolarization.

Coexistence of congenital left ventricular aneurysm and prominent left ventricular trabeculation in a patient with LDB3 mutation: a case report.

PubMed

Shan, Shengshuai; He, Xiaoxiao; He, Lin; Wang, Min; Liu, Chengyun

2017-08-19

The coexistence of congenital left ventricular aneurysm and abnormal cardiac trabeculation with gene mutation has not been reported previously. Here, we report a case of coexisting congenital left ventricular aneurysm and prominent left ventricular trabeculation in a patient with LIM domain binding 3 gene mutation. A 30-year-old Asian man showed paroxysmal sinus tachycardia and Q waves in an electrocardiogram health check. There were no specific findings in physical examinations and serological tests. A coronary-computed tomography angiography check showed normal coronary artery and no coronary stenosis. Both left ventricle contrast echocardiography and cardiac magnetic resonance showed rare patterns of a combination of an apical aneurysm-like out-pouching structure with a wide connection to the left ventricle and prominent left ventricular trabecular meshwork. High-throughput sequencing examinations showed a novel mutation in the LDB3 gene (c.C793>T; p.Arg265Cys). Our finding indicates that the phenotypic expression of two heart conditions, congenital left ventricular aneurysm and prominent left ventricular trabeculation, although rare, can occur simultaneously with LDB3 gene mutation. Congenital left ventricular aneurysm and prominent left ventricular trabeculation may share the same genetic background.

Cardiovascular haemodynamics and cardiac autonomic control in patients with subclinical and overt hyperthyroidism.

PubMed

Petretta, M; Bonaduce, D; Spinelli, L; Vicario, M L; Nuzzo, V; Marciano, F; Camuso, P; De Sanctis, V; Lupoli, G

2001-12-01

To characterize cardiac structure and function and cardiac autonomic control in patients with subclinical and overt hyperthyroidism. Thirty patients with subclinical hyperthyroidism and 30 with overt disease were selected from patients never previously treated for endocrinological disease in the outpatient clinic of our institution. Twenty normal individuals were studied as control group. Left ventricular structure and function and cardiac autonomic control were evaluated, respectively, by two-dimensional Doppler echocardiography and by 24-h Holter recording with heart rate variability analysis. Patients with overt hyperthyroidism showed greater values of left ventricular end-diastolic volume (P<0.05) and left ventricular mass (P<0.05) than patients with subclinical disease. In addition, the mean velocity of left ventricular fibre shortening (P<0.05) and left ventricular ejection fraction (P<0.05) were greater in patients with overt hyperthyroidism than in patients with subclinical disease. No difference in any of these parameters was detectable between normal subjects and patients with subclinical disease. The isovolumic relaxation period was shorter in patients with subclinical hyperthyroidism than in control individuals (P<0.05) and in patients with overt hyperthyroidism (P<0.05). As regards cardiac autonomic control, all time and frequency domain measures decreased progressively from control individuals to patients with subclinical hyperthyroidism and those with overt disease (P<0.001). Thyrotoxic patients show changes in left ventricular structure and increased echocardiographic indexes of myocardial contractility, whereas the only echocardiographic feature detectable in patients with subclinical hyperthyroidism is an increased velocity of left ventricular relaxation. Cardiac parasympathetic withdrawal is evident in patients with overt hyperthyroidism and in patients with subclinical disease.

The Biological Role of Nestin(+)-Cells in Physiological and Pathological Cardiovascular Remodeling

PubMed Central

Calderone, Angelino

2018-01-01

The intermediate filament protein nestin was identified in diverse populations of cells implicated in cardiovascular remodeling. Cardiac resident neural progenitor/stem cells constitutively express nestin and following an ischemic insult migrate to the infarct region and participate in angiogenesis and neurogenesis. A modest number of normal adult ventricular fibroblasts express nestin and the intermediate filament protein is upregulated during the progression of reparative and reactive fibrosis. Nestin depletion attenuates cell cycle re-entry suggesting that increased expression of the intermediate filament protein in ventricular fibroblasts may represent an activated phenotype accelerating the biological impact during fibrosis. Nestin immunoreactivity is absent in normal adult rodent ventricular cardiomyocytes. Following ischemic damage, the intermediate filament protein is induced in a modest population of pre-existing adult ventricular cardiomyocytes bordering the peri-infarct/infarct region and nestin(+)-ventricular cardiomyocytes were identified in the infarcted human heart. The appearance of nestin(+)-ventricular cardiomyocytes post-myocardial infarction (MI) recapitulates an embryonic phenotype and depletion of the intermediate filament protein inhibits cell cycle re-entry. Recruitment of the serine/threonine kinase p38 MAPK secondary to an overt inflammatory response after an ischemic insult may represent a seminal event limiting the appearance of nestin(+)-ventricular cardiomyocytes and concomitantly suppressing cell cycle re-entry. Endothelial and vascular smooth muscle cells (VSMCs) express nestin and upregulation of the intermediate filament protein may directly contribute to vascular remodeling. This review will highlight the biological role of nestin(+)-cells during physiological and pathological remodeling of the heart and vasculature and discuss the phenotypic advantage attributed to the intermediate filament protein. PMID:29492403

Size, shape, and stamina: the impact of left ventricular geometry on exercise capacity.

PubMed

Lam, Carolyn S P; Grewal, Jasmine; Borlaug, Barry A; Ommen, Steve R; Kane, Garvan C; McCully, Robert B; Pellikka, Patricia A

2010-05-01

Although several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction > or = 50% and no valvular disease, myocardial ischemia, or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. All of the subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60+/-14 years; 57% male) subjects, 166 (45%) had normal geometry, 106 (29%) had concentric remodeling, 40 (11%) had eccentric hypertrophy, and 54 (15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents were 9.9+/-2.8 in normal, 8.9+/-2.6 in concentric remodeling, 8.6+/-3.1 in eccentric hypertrophy, and 8.0+/-2.7 in concentric hypertrophy (all P<0.02 versus normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r=-0.14; P=0.009 and r=-0.21; P<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared with normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation, and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease.

Size, Shape and Stamina: The Impact of Left Ventricular Geometry on Exercise Capacity

PubMed Central

Lam, Carolyn S.P.; Grewal, Jasmine; Borlaug, Barry A.; Ommen, Steve R.; Kane, Garvan C.; McCully, Robert B.; Pellikka, Patricia A.

2010-01-01

While several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction ≥ 50% and no valvular disease, myocardial ischemia or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy and concentric hypertrophy. All subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60±14 years; 57% male) subjects, 166(45%) had normal geometry, 106(29%) had concentric remodeling, 40(11%) had eccentric hypertrophy and 54(15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents was 9.9±2.8 in normal, 8.9±2.6 in concentric remodeling, 8.6±3.1 in eccentric hypertrophy and 8.0±2.7 in concentric hypertrophy (all p<0.02 vs normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r= -0.14; p=0.009 and r= -0.21; p<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared to normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease. PMID:20215563

Significant effects of atrioventricular node ablation and pacemaker implantation on left ventricular function and long-term survival in patients with atrial fibrillation and left ventricular dysfunction.

PubMed

Ozcan, Cevher; Jahangir, Arshad; Friedman, Paul A; Munger, Thomas M; Packer, Douglas L; Hodge, David O; Hayes, David L; Gersh, Bernard J; Hammill, Stephen C; Shen, Win-Kuang

2003-07-01

Control of ventricular rate by atrioventricular node ablation and pacemaker implantation in patients with drug-refractory atrial fibrillation (AF) is associated with improved left ventricular (LV) function. The objective of this study was to determine the effect of atrioventricular node ablation on long-term survival in patients with AF and LV dysfunction. Survival was determined by the Kaplan-Meier method for 56 study patients with LV ejection fraction (EF) < or =40% who underwent atrioventricular node ablation and pacemaker implantation and 56 age- and gender-matched control patients with AF and LVEF >40%, and age- and gender-matched control subjects from Minnesota. Groups were compared using the log-rank test. In study patients (age 69 +/- 10 years; 45 men), LVEF was 26% +/- 8% and 34% +/- 13% (p <0.001) before and after ablation, respectively. During follow-up (40 +/- 23 months), 23 patients died. Observed survival was worse than that of normal subjects (p <0.001) and control patients (p = 0.005). After ablation, LVEF nearly normalized (> or =45%) in 16 study patients (29%), in whom observed survival was comparable to that of normal subjects (p = 0.37). Coronary artery disease, hyperlipidemia, chronic renal failure, previous myocardial infarction, and coronary artery operation were independent predictors for mortality. Near normalization of LVEF occurred in 29% of study patients, suggesting that AF-induced EF reduction is reversible in many patients. Normal survival in patients with reversible LV dysfunction highlights potential survival benefits of rate control. Poor survival in patients with persistent LV dysfunction confirms the importance of optimal medical therapy.

Soft J-tipped guide wire-induced cardiac perforation in a patient with right ventricular lipomatosis and wall thinning.

PubMed

Hiroshima, Yuki; Tajima, Katsushi; Shiono, Yousuke; Suzuki, Ikuko; Kohno, Kei; Kato, Yuichi; Shunji, Kawamura; Kato, Takeo

2012-01-01

Cardiac tamponade caused by perforation is a rare but potentially lethal complication of central venous catheter (CVC) insertion. We herein report a case of cardiac perforation associated with the use of a soft J-tipped guide wire. Twenty minutes after the insertion of a CVC, the patient developed unexpected cardiac arrest. An autopsy revealed 400 mL of pericardial blood. The right ventricular wall was 1 mm thick with about 10 myocyte layers, which is one-third that of the normal heart. A histological analysis revealed widespread fatty infiltration of the right ventricular wall (right ventricular lipomatosis).

Evolving J waves prior to ventricular fibrillation postoperative coronary bypass.

PubMed

Kitazawa, Hitoshi; Wakasugi, Takayuki; Sugimoto, Tsutomu; Yamamoto, Kazuo; Yoshii, Shinpei; Aizawa, Yoshifusa

2011-01-01

A 74-year-old man without history of ventricular arrhythmias underwent coronary bypass surgery for 3-vessel disease. On the 4th postoperative day, he developed ventricular fibrillation (VF). His monitored ECG showed no elevation of the ST-segment and no prolongation of QT interval, but evolving J waves prior to VF were shown. These J waves gradually decreased after defibrillation. The subsequent angiography revealed patent grafts and normal left ventricular function. J waves reappeared in inferior leads when contrast medium was injected into the coronary artery. Therefore, evolving J wave can be a marker of latent ischemia and a predictor of VF.

Clinical applications of angiocardiography

NASA Technical Reports Server (NTRS)

Dodge, H. T.; Sandler, H.

1974-01-01

Several tables are presented giving left ventricular (LV) data for normal patients and patients with heart disease of varied etiologies, pointing out the salient features. Graphs showing LV pressure-volume relationships (compliance) are presented and discussed. The method developed by Rackley et al. (1964) for determining left ventricular mass in man is described, and limitations to the method are discussed. Some clinical methods for determining LV oxygen consumption are briefly described, and the relation of various abnormalities of ventricular performance to coronary artery disease and ischemic heart disease is characterized.

[Two stage surgical treatment of large ventricular septal defects (author's transl)].

PubMed

Hoffmeister, H E; Seybold-Epting, W; Stunkat, R

1976-12-01

Since March 1971, 51 infants were subjected to pulmonary artery banding (PAB) for a large ventricular septal defect (VSD) with pulmonary hypertension. 41 infants (80%) were under six months of age. Additional defects were present in 41%. Twelve babies died (24%). The lowest mortality was achieved in isolated VSD (6,7%). 28 patients subsequently underwent VSD closure and pulmonary artery debanding. Catheterization data revealed normal or slightly elevated pressures and normal vascular resistance in the pulmonary circuit in 22 children. The operative mortality rate was 10,7%.

Pacemaker syndrome with sub-acute left ventricular systolic dysfunction in a patient with a dual-chamber pacemaker: consequence of lead switch at the header.

PubMed

Khurwolah, Mohammad Reeaze; Vezi, Brian Zwelethini

In the daily practice of pacemaker insertion, the occurrence of atrial and ventricular lead switch at the pacemaker box header is a rare and unintentional phenomenon, with less than five cases reported in the literature. The lead switch may have dire consequences, depending on the indication for the pacemaker. One of these consequences is pacemaker syndrome, in which the normal sequence of atrial and ventricular activation is impaired, leading to sub-optimal ventricular filling and cardiac output. It is important for the attending physician to recognise any worsening of symptoms in a patient who has recently had a permanent pacemaker inserted. In the case of a dual-chamber pacemaker, switching of the atrial and ventricular leads at the pacemaker box header should be strongly suspected. We present an unusual case of pacemaker syndrome and right ventricular-only pacinginduced left ventricular systolic dysfunction in a patient with a dual-chamber pacemaker.

Localisation of atrial natriuretic peptide immunoreactivity in the ventricular myocardium and conduction system of the human fetal and adult heart.

PubMed Central

Wharton, J; Anderson, R H; Springall, D; Power, R F; Rose, M; Smith, A; Espejo, R; Khaghani, A; Wallwork, J; Yacoub, M H

1988-01-01

Atrial natriuretic peptide immunoreactivity was found in ventricular and atrial tissues with specific antisera raised to the amino and carboxy terminal regions of the precursor molecule. In 13 developing human hearts (7-24 weeks' gestation) the immunoreactivity was concentrated in the atrial myocardium and ventricular conduction system but it was also detected in the early fetal ventricular myocardium. Immunoreactivity in five normal adults was largely confined to the atrial myocardium although it was also found in the ventricular conduction tissues of hearts removed from 10 patients who were undergoing cardiac transplantation. The ventricular conduction system is an extra-atrial site for the synthesis of atrial natriuretic peptide. In the failing heart this synthesis may be further supplemented by expression of the gene in the ventricular myocardium. It is possible that ventricular production of the peptide contributes to the raised circulating concentrations of atrial natriuretic peptide immunoreactivity found in severe congestive heart disease, particularly in patients with dilated cardiomyopathy. Images Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 PMID:2973340

Ventricular Diastolic Function in Normal Fetuses and Fetuses with Hb Bart's Disease Assessed by Color M-Mode Propagation Velocity using Cardio-STIC-M (Spatio-Temporal Image Correlation M-Mode).

PubMed

Tongsong, T; Tongprasert, F; Srisupundit, K; Luewan, S; Traisrisilp, K

2016-10-01

Purpose: To determine whether ventricular diastolic dysfunction contributes to the pathogenesis of fetal cardiac failure due to fetal anemia using fetal Hb Bart's disease as a live model and cardio-STIC-M as a diagnostic tool. Materials and Methods: Color cardio-STIC volume datasets were acquired from fetuses at risk for Hb Bart's disease during 18 - 22 weeks of gestation and normal pregnancies and pregnancies with hydrops fetalis caused by Hb Bart's disease at 28 - 32 weeks. The volumes were analyzed off-line for velocity propagation (Vp) of the right and left ventricles to assess ventricular diastolic function using color cardio-STIC-M. Results: The Vp for the right and left ventricles was studied in fetuses at 18 - 22 weeks, including 64 normal fetuses (group 1) and 22 fetuses with Hb Bart's disease (group 2), and in fetuses at 28 - 32 weeks, including 22 normal fetuses (group 3) and 16 fetuses with Hb Bart's hydrops fetalis (group 4). The Vp of the fetuses in group 1 and group 2 was not significantly different. However, the Vp for the right and left ventricles in group 4 was significantly lower than in group 3 (19.02 vs. 9.78, p < 0.001; and 20.24 vs. 13.40, p < 0.001, respectively). The inter-observer variability had fair agreement with the intra-class correlation coefficient of 0.531 (95 % CI 0.393 - 0.646, p < 0.001). Conclusion: Hydrops fetalis secondary to fetal anemia is initially caused by hypervolemia rather than ventricular diastolic dysfunction while ventricular diastolic compromise is a late occurring consequence of persistent hypervolemia, different from the mechanism of hydropic changes caused by cardiac causes. © Georg Thieme Verlag KG Stuttgart · New York.

Long-term neurodevelopmental outcome and exercise capacity after corrective surgery for tetralogy of Fallot or ventricular septal defect in infancy.

PubMed

Hövels-Gürich, Hedwig H; Konrad, Kerstin; Skorzenski, Daniela; Nacken, Claudia; Minkenberg, Ralf; Messmer, Bruno J; Seghaye, Marie-Christine

2006-03-01

The purpose of this prospective study was to assess whether neurodevelopmental status and exercise capacity of children 5 to 10 years after corrective surgery for tetralogy of Fallot or ventricular septal defect in infancy was different compared with normal children and influenced by the preoperative condition of hypoxemia or cardiac insufficiency. Forty unselected children, 20 with tetralogy of Fallot and hypoxemia and 20 with ventricular septal defect and cardiac insufficiency, operated on with combined deep hypothermic circulatory arrest and low flow cardiopulmonary bypass at a mean age of 0.7 +/- 0.3 years (mean +/- SD), underwent, at mean age 7.4 +/- 1.6 years, standardized evaluation of neurologic status, gross motor function, intelligence, academic achievement, language, and exercise capacity. Results were compared between the groups and related to preoperative, perioperative, and postoperative status and management. Rate of mild neurologic dysfunction was increased compared with normal children, but not different between the groups. Exercise capacity and socioeconomic status were not different compared with normal children and between the groups. Compared with the normal population, motor function, formal intelligence, academic achievement, and expressive and receptive language were significantly reduced (p < 0.01 to p < 0.001) in the whole group and in the subgroups, except for normal intelligence in ventricular septal defect patients. Motor dysfunction was significantly higher in the Fallot group compared with the ventricular septal defect group (p < 0.01) and correlated with neurologic dysfunction, lower intelligence, and reduced expressive language (p < 0.05 each). Reduced New York Heart Association functional class was correlated with lower exercise capacity and longer duration of cardiopulmonary bypass (p < 0.05 each). Reduced socioeconomic status significantly influenced dysfunction in formal intelligence (p < 0.01) and academic achievement (p < 0.05). Preoperative risk factors such as prenatal hypoxia, perinatal asphyxia, and preterm birth, factors of perioperative management such as cardiac arrest, lowest nasopharyngeal temperature, and age at surgery, and postoperative risk factors as postoperative cardiocirculatory insufficiency and duration of mechanical ventilation were not different between the groups and had no influence on outcome. Degree of hypoxemia in Fallot patients and degree of cardiac insufficiency in ventricular septal defect patients did not influence the outcome within the subgroups. Children with preoperative hypoxemia in infancy are at higher risk for motor dysfunction than children with cardiac insufficiency. Corrective surgery in infancy for tetralogy of Fallot or ventricular septal defect with combined circulatory arrest and low flow bypass is associated with reduced neurodevelopmental outcome, but not with reduced exercise capacity in childhood. In our experience, the general risk of long-term neurodevelopmental impairment is related to unfavorable effects of the global perioperative management. Socioeconomic status influences cognitive capabilities.

Mitral valve coaptation and its relationship to late diastolic flow: A color Doppler and vector flow map echocardiographic study in normal subjects.

PubMed

Sherrid, Mark V; Kushner, Josef; Yang, Georgiana; Ro, Richard

2017-04-01

Three competing theories about the mechanism of mitral coaptation in normal subjects were evaluated by color Doppler and vector flow mapping (VFM): (1) beginning of ventricular (LV) ejection, (2) "breaking of the jet" of diastolic LV inflow, and (3) returning diastolic vortices impacting the leaflets on their LV surfaces. We analyzed 80 color Doppler frames and 320 VFM measurements. In all 20 normal subjects, coaptation occurred before LV ejection, 78±16 ms before onset. On color Doppler frames the larger anterior, and smaller posterior vortices circle back and, in all cases, strike the ventricular surfaces of the leaflets. On the first closing-begins frame, for the first time, vortex velocity normal to the ventricular surface of the anterior leaflet (AML) is greater than that in the mitral orifice, and the angle of attack of LV vortical flow onto the AML is twice as high as the angle of flow onto the valve in orifice. Thus, at the moment coaptation begins, vortical flow strikes the mitral leaflet with higher velocity, and higher angle of attack than orifice flow, and thus with greater force. According to the "breaking of the jet" theory, one would expect to see de novo LV flow perpendicular to the leaflets beginning after transmitral flow terminates. Instead, the returning continuous LV vortical flow that impacts the valve builds continuously after the P-wave. Late diastolic vortices strike the ventricular surfaces of the mitral leaflets and contribute to valve coaptation, permitted by concomitant decline in transmitral flow. © 2017, Wiley Periodicals, Inc.

Right ventricular performance and mass by use of cine MRI late after atrial repair of transposition of the great arteries.

PubMed

Lorenz, C H; Walker, E S; Graham, T P; Powers, T A

1995-11-01

The long-term adaptation of the right ventricle after atrial repair of transposition of the great arteries (TGA) remains a subject of major concern. Cine magnetic resonance imaging (MRI), with its tomographic capabilities, allows unique quantitative evaluation of both right and left ventricular function and mass. Our purpose was to use MRI and an age-matched normal population to examine the typical late adaptation of the right and left ventricles after atrial repair of TGA. Cine MRI was used to study ventricular function and mass in 22 patients after atrial repair of TGA. Images were obtained in short-axis sections from base to apex to derive normalized right and left ventricular mass (RVM and LVM, g/m2), interventricular septal mass (IVSM, g/m2), RV and LV end-diastolic volumes (EDV, mL/m2), and ejection fractions (EF). Results 8 to 23 years after repair were compared with analysis of 24 age- and sex-matched normal volunteers and revealed markedly elevated RVM, decreased LVM and IVSM, normal RV size, and only mildly depressed RVEF. Only 1 of 22 patients had clinical RV dysfunction, and this patient had increased RVM. Cine MRI allows quantitative evaluation of both RV and LV mass and function late after atrial repair of TGA. Longitudinal studies that include these measurements should prove useful in determining the mechanism of late RV failure in these patients. On the basis of these early data, inadequate hypertrophy does not appear to be the cause of late dysfunction in this patient group.

[Contribution of phase-contrast MRI to the management of patients with normal pressure hydrocephalus: Can it predict response to shunting?].

PubMed

Mouton Paradot, Gaëlle; Baledent, Olivier; Sallioux, Guillaume; Lehmann, Pierre; Gondry-Jouet, Catherine; Le Gars, Daniel

2010-02-01

The diagnosis and management of patients with idiopathic normal-pressure hydrocephalus (NPH) remain somewhat controversial and there is no clear guideline for assessing the post-shunt outcome. The objective of this study was to investigate whether cerebrospinal fluid (CSF) flow dynamics is linked to post-shunt improvement. Fourteen NPH patients (nine males and five females; mean age, 68 years) investigated by magnetic resonance imaging (MRI) before surgical diversion of CSF were retrospectively reviewed. Phase-contrast sequences were added to the morphological clinical protocol for quantification of CSF oscillations, which were recorded at the level of the cerebral aqueduct and the C2 and C3 subarachnoid spaces (SAS). The phase-contrast images were analysed with custom-designed dedicated flow segmentation software. The oscillations measured in this hydrocephalus population were compared to a previously studied healthy population. A difference of at least two standard deviations was used to define a hyperdynamic or hypodynamic state of CSF flow. The cervical CSF flow of the hydrocephalus patients was not significantly different from those of the volunteer population. Of the 14 hydrocephalus patients, 12 had a good response to the shunt. Of these, 10 presented an increased ventricular CSF flow, one a low ventricular CSF flow, and the last one had a normal ventricular CSF flow. Phase-contrast MRI can help develop guidelines for surgical management of NPH. The shunt responders appear to be the patients with hyperdynamic ventricular CSF flow and normal cervical CSF flow. Copyright 2009 Elsevier Masson SAS. All rights reserved.

Magnetic resonance imaging analysis of cardiac cycle events in diabetic rats: the effect of angiotensin-converting enzyme inhibition

PubMed Central

Al-Shafei, Ahmad I M; Wise, R G; Gresham, G A; Carpenter, T A; Hall, L D; Huang, Christopher L-H

2002-01-01

Non-invasive magnetic resonance imaging (MRI) was used to characterize changes in left and right ventricular cardiac cycles following induction of experimental, streptozotocin (STZ)-induced, diabetes in male Wistar rats at different ages. The effects of the angiotensin-converting enzyme (ACE) inhibitor captopril upon such chronic physiological changes were then evaluated, also for the first time. Diabetes was induced at the age of 7 weeks in two experimental groups, of which one group was subsequently maintained on captopril (2 g l−1)-containing drinking water, and at 10 and 13 weeks in two further groups. The fifth group provided age-matched controls. All groups (each n = 4 animals) were scanned consistently at 16 weeks, in parallel with timings used in earlier studies that employed this experimental model. Cine magnetic resonance (MR) image acquisition provided transverse sections through both ventricles at twelve time points covering systole and most of diastole. These yielded reconstructions of cardiac anatomy used to derive critical functional indices and their dependence upon time following the triggering electrocardiographic R waves. The left and right ventricular end-diastolic (EDV), end-systolic (ESV) and stroke volumes (SV), and ejection fractions (EF) calculated from each, control and experimental, group showed matching values. This confirmed a necessary condition requiring balanced right and left ventricular outputs and further suggested that STZ-induced diabetes produced physiological changes in both ventricles. Absolute left and right ventricular SVs were significantly altered in all diabetic animals; EDVs and EFs significantly altered in animals diabetic from 7 and 10 but not 13 weeks. When normalized to body weight, left and right ventricular SVs had significantly altered in animals diabetic from 7 and 10 weeks but not 13 weeks. Normalized left ventricular EDVs were also significantly altered in animals diabetic from 7 and 10 weeks. However, normalized right ventricular EDVs were significantly altered only in animals made diabetic from 7 weeks. Diabetic hearts showed major kinetic changes in left and right ventricular contraction (ejection) and relaxation (filling). Both the initial rates of volume change (dV/dt) in both ventricles and the plots of dV/dt values through the cardiac cycle demonstrated more gradual developments of tension during systole and relaxation during diastole. Estimates of the derived left ventricular performance parameters of cardiac output, cardiac power output and stroke work in control animals were comparable with human values when normalized to both body (or cardiac) weight and heart rate. All deteriorated with diabetes. Comparisons of experimental groups diabetic from 7 weeks demonstrated that captopril treatment relieved the alterations in critical volumes, dependence of SV upon EDV, kinetics of systolic contraction and diastolic relaxation and in the derived indicators of ventricular performance. This study represents the first demonstration using non-invasive MRI of early, chronic changes in diastolic filling and systolic ejection in both the left and the right ventricles and of their amelioration by ACE inhibition following STZ-induction of diabetes in intact experimental animals. PMID:11790819

[Loss of capture by myocardial ischemia: A case report].

PubMed

Sonou, A; Adjagba, P M; Hounkponou, M; Codjo, L; Houéhanou-Sonou, C; Assani, S; Yessoufou, T; Sacca, J; Houénassi, M

2017-02-01

We report the case of a patient with pacemaker who presented chest pain during exercise followed by fainting. He has a history of arterial hypertension and diabetes. The initial examination was normal; the ventricular stimulation threshold was 1.125 volts (V) and cardiac enzymes were normal. Stress test has reproduced chest pain followed by loss of pacemaker capture and asystole. Coronary angiography showed a tight stenosis of the proximal anterior interventricular artery dilated by a drug-eluting stent. The control of stress test was normal. A stent thrombosis eight days later led to an acute coronary syndrome with recurrent syncope due to the loss of ventricular capture. The ventricular pacing threshold was then 2.25V. After revascularization and stabilization of the patient's clinical status, this threshold returned to 1.125V. This clinic case has confirmed that coronary artery disease could increase pacing threshold. It also highlights the usefulness of automatic capture algorithms in coronary patients. The stress test cannot only help to detect coronary artery disease but also allows the optimization of programming the pacemaker. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Carotid artery stiffness evaluated early by wave intensity in normal left ventricular function in post-radiotherapy patients with nasopharyngeal carcinoma.

PubMed

Zhang, Zhuo; Luo, Runlan; Tan, Bijun; Qian, Jing; Duan, Yanfang; Wang, Nan; Li, Guangsen

2018-04-01

This study aims to assess carotid elasticity early in normal left ventricular function in post-radiotherapy patients with nasopharyngeal carcinoma (NPC) by wave intensity. Sixty-seven post-radiotherapy patients all with normal left ventricular function were classified into group NPC1 and group NPC2 based on their carotid intima-media thickness. Thirty age- and sex-matched NPC patients without any history of irradiation and chemotherapy were included as a control group. Carotid parameters, including stiffness constant (β), pressure-strain elastic modulus (Ep), arterial compliance (AC), stiffness constant pulse wave velocity (PWVβ), and wave intensity pulse wave velocity (PWVWI) were measured. There were no significant differences in conventional echocardiographic variables among the three groups. In comparison with the control group, β, Ep, PWVβ, and PWVWI were significantly increased, while AC was significantly decreased in the NPC1 and NPC2 groups, and there were differences between the NPC1 group and NPC2 group (all P < 0.05). This study suggested that carotid artery stiffness increased with reduced carotid compliance in post-RT with NPC.

Impact of age and sex on normal left heart structure and function.

PubMed

Hagström, Linn; Henein, Michael Y; Karp, Kjell; Waldenström, Anders; Lindqvist, Per

2017-11-01

Accurate age- and sex-related normal reference values of ventricular structure and function are important to determine the level of dysfunction in patients. The aim of this study therefore was to document normal age range sex-related measurements of LV structural and functional measurements to serve such purpose. We evaluated left ventricular structure and function in 293 healthy subjects between 20 and 90 years with equally distributed gender. Doppler echocardiography was used including measure of both systolic and diastolic functions. Due to systolic LV function, only long axis function correlated with age (r = 0·55, P<0·01) and the correlation was stronger in females. Concerning diastolic function, there was a strong age correlation in all parameters used (r = 0·40-0·74, P<0·001). Due to LV structural changes over age, females showed a larger reduction in end-diastolic volumes, but no or trivial difference in wall thickness after the age of 60 years. Age is associated with significant normal changes in left ventricular structure and function, which should be considered when deciding on normality. These changes are related to systemic arterial changes as well as body stature, thus reflecting overall body ageing process. Furthermore, normal cardiac ageing in females might partly explain the higher prevalence of heart failure with preserved ejection in females. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Role of apamin-sensitive small conductance calcium-activated potassium currents in long-term cardiac memory in rabbits.

PubMed

Yin, Dechun; Chen, Mu; Yang, Na; Wu, Adonis Z; Xu, Dongzhu; Tsai, Wei-Chung; Yuan, Yuan; Tian, Zhipeng; Chan, Yi-Hsin; Shen, Changyu; Chen, Zhenhui; Lin, Shien-Fong; Weiss, James N; Chen, Peng-Sheng; Everett, Thomas H

2018-05-01

Apamin-sensitive small conductance calcium-activated K current (I KAS ) is up-regulated during ventricular pacing and masks short-term cardiac memory (CM). The purpose of this study was to determine the role of I KAS in long-term CM. CM was created with 3-5 weeks of ventricular pacing and defined by a flat or inverted T wave off pacing. Epicardial optical mapping was performed in both paced and normal ventricles. Action potential duration (APD 80 ) was determined during right atrial pacing. Ventricular stability was tested before and after I KAS blockade. Four paced hearts and 4 normal hearts were used for western blotting and histology. There were no significant differences in either echocardiographic parameters or fibrosis levels between groups. Apamin induced more APD 80 prolongation in CM than in normal ventricles (mean [95% confidence interval]: 9.6% [8.8%-10.5%] vs 3.1% [1.9%-4.3%]; P <.001). Apamin significantly lengthened APD 80 in the CM model at late activation sites, indicating significant I KAS up-regulation at those sites. The CM model also had altered Ca 2+ handling, with the 50% Ca 2+ transient duration and amplitude increased at distal sites compared to a proximal site (near the pacing site). After apamin, the CM model had increased ventricular fibrillation (VF) inducibility (paced vs control: 33/40 (82.5%) vs 7/20 (35%); P <.001) and longer VF durations (124 vs 26 seconds; P <.001). Chronic ventricular pacing increases Ca 2+ transients at late activation sites, which activates I KAS to maintain repolarization reserve. I KAS blockade increases VF vulnerability in chronically paced rabbit ventricles. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Carotid atherosclerosis and right ventricular diastolic dysfunction in a sample of hypertensive Nigerian patients

PubMed Central

Akintunde, Adeseye A.; Adebayo, Philip B.; Aremu, Ademola A.; Opadijo, Oladimeji G.

2013-01-01

Aim To determine the association of carotid atherosclerosis and right ventricular diastolic dysfunction (DD) among treated hypertensive Nigerian patients. Methods This was a single center cross-sectional study performed at the Cardiology Clinic of LAUTECH Teaching Hospital, Ogbomoso, Nigeria between January and December 2012. The study included 122 hypertensive Nigerians (mean age, 57.3 ± 14.7 years, 36.9% women). Patients’ clinical, demographic, and echocardiographic parameters were obtained. Diastolic dysfunction was assessed with the trans-tricuspid Doppler flow. Results Patients with DD were significantly older than those with normal diastolic function. Mean and maximum carotid intima media thickness measurements were significantly higher among patients with right ventricular DD than in those with normal diastolic function. Mean systolic blood pressure (148.3 ± 31.9 vs 128.0 ± 2.8 mm Hg, P = 0.049) and interventricular septal thickness in diastole (12.8 ± 2.3 vs 11.6 ± 2.8mm, P = 0.048) were significantly higher and tricuspid annular pulmonary systolic excursion (33.6 ± 4.9 vs 23.0 ± 4.2 mm, P = 0.035) was significantly lower in patients with right ventricular DD than in those with normal diastolic function. Carotid intima media thickness measurements were correlated with early trans-tricuspid Doppler flow and early transtricuspid diastolic flow/late right atrial transtricupsid diastolic flow ratio. Conclusion Right ventricular DD in hypertensive patients was significantly correlated with increased carotid atherosclerosis. Carotid intima media thickness measurements may therefore be a surrogate marker for DD in hypertensive subjects. PMID:24382850

Evaluation of left ventricular performance during supine exercise by transoesophageal M-mode echocardiography in normal subjects.

PubMed Central

Matsumoto, M; Hanrath, P; Kremer, P; Tams, C; Langenstein, B A; Schlüter, M; Weiter, R; Bleifeld, W

1982-01-01

In order to evaluate left ventricular function during dynamic exercise transoesophageal M-mode recordings of the left ventricle were carried out with a newly developed transducer gastroscope system. Twelve healthy subjects performed a graded supine bicycle exercise test. Stable and good quality images of the left ventricle at rest and during exercise at different steps up to a maximum workload of 100 watts were obtained in all patients. Isotonic maximum exercise resulted in a significant increase in fractional shortening of the left ventricle, peak shortening rate, and peak lengthening rate of the left ventricular minor axis. Left ventricular end-diastolic dimension decreased significantly. With increasing workload the pressure rate product increased significantly. It is concluded that transoesophageal M-mode echocardiography is a useful method of evaluating left ventricular performance during dynamic exercise. Images PMID:7082515

Kawasaki syndrome in an adult: endomyocardial histology and ventricular function during acute and recovery phases of illness.

PubMed

Marcella, J J; Ursell, P C; Goldberger, M; Lovejoy, W; Fenoglio, J J; Weiss, M B

1983-08-01

Kawasaki syndrome, an acute systemic inflammatory illness of unknown origin usually affecting children, may develop into a serious illness complicated by coronary artery aneurysms or myocarditis. This report describes an adult with Kawasaki syndrome studied by right ventricular endomyocardial biopsy and cardiac catheterization during the acute and recovery phases of illness. The initial biopsy specimen showed acute myocarditis and was associated with hemodynamic evidence of biventricular dysfunction, a severely depressed left ventricular ejection fraction and global hypokinesia. With time, there was spontaneous and rapid resolution of the inflammatory cell infiltrate with concurrent return to normal myocardial function. Right ventricular endomyocardial biopsy studies early in the course of the cardiac disease associated with Kawasaki syndrome may correlate with ventricular function and may be useful for monitoring immunosuppressive therapy in patients with this syndrome.

Computational model based approach to analysis ventricular arrhythmias: Effects of dysfunction calcium channels

NASA Astrophysics Data System (ADS)

Gulothungan, G.; Malathi, R.

2018-04-01

Disturbed sodium (Na+) and calcium (Ca2+) handling is known to be a major predisposing factor for life-threatening cardiac arrhythmias. Cardiac contractility in ventricular tissue is prominent by Ca2+ channels like voltage dependent Ca2+ channels, sodium-calcium exchanger (Na+-Ca2+x) and sacroplasmicrecticulum (SR) Ca2+ pump and leakage channels. Experimental and clinical possibilities for studying cardiac arrhythmias in human ventricular myocardium are very limited. Therefore, the use of alternative methods such as computer simulations is of great importance. Our aim of this article is to study the impact on action potential (AP) generation and propagation in single ventricular myocyte and ventricular tissue under different dysfunction Ca2+ channels condition. In enhanced activity of Na+-Ca2+x, single myocyte produces AP duration (APD90) and APD50 is significantly smaller (266 ms and 235 ms). Its Na+-Ca2+x current at depolarization is increases 60% from its normal level and repolarization current goes more negative (nonfailing= -0.28 pA/pF and failing= -0.47 pA/pF). Similarly, same enhanced activity of Na+-Ca2+x in 10 mm region of ventricular sheet, raises the plateau potential abruptly, which ultimately affects the diastolic repolarization. Compare with normal ventricular sheet region of 10 mm, 10% of ventricular sheet resting state is reduces and ventricular sheet at time 250 ms is goes to resting state very early. In hypertrophy condition, single myocyte produces APD90 and APD50 is worthy of attention smaller (232 mS and 198 ms). Its sodium-potassium (Na+-K+) pump current is 75% reduces from its control conditions (0.13 pA/pF). Hypertrophy condition, 50% of ventricular sheet is reduces to minimum plateau potential state, that starts the repolarization process very early and reduces the APD. In a single failing SR Ca2+ channels myocyte, recovery of Ca2+ concentration level in SR reduces upto 15% from its control myocytes. At time 290 ms, 70% of ventricular sheet is in dysfunction resting potential state in the range -83 mV and ventricular sheet at time 295 ms is goes to 65% dysfunction resting state. Therefore we concluded that shorter APD, instability resting potential and affected calcium induced calcium release (CICR) due to dysfunction Ca2+ channels is potentially have a substantial effect on cardiac contractility and relaxation. Computational study on ventricular tissue AP and its underlying ionic channel currents could help to elucidate possible arrhythmogenic mechanism on a cellular level.

Effect of varying ventricular function by extrasystolic potentiation on closure of the mitral valve.

NASA Technical Reports Server (NTRS)

Vandenberg, R. A.; Williams, J. C. P.; Sturm, R. E.; Wood , E. H.

1971-01-01

Mitral regurgitant indexes were measured by roentgen videodensitometry in anesthetized dogs without thoracotomy before, during and after extrasystolic potentiation of ventricular contraction while the atria and ventricles were driven in normal temporal sequence simultaneously or in such a way as to induce atrial fibrillation. Small amounts of mitral reflux were observed with simultaneous atrial and ventricular driving and with atrial fibrillation in the control measurements before initiation of extrasystolic potentiation. Reflux became negligible during extrasystolic potentiation and increased beyond control levels after termination of extrasystolic potentiation.

Quasiperiodicity route to chaos in cardiac conduction model

NASA Astrophysics Data System (ADS)

Quiroz-Juárez, M. A.; Vázquez-Medina, R.; Ryzhii, E.; Ryzhii, M.; Aragón, J. L.

2017-01-01

It has been suggested that cardiac arrhythmias are instances of chaos. In particular that the ventricular fibrillation is a form of spatio-temporal chaos that arises from normal rhythm through a quasi-periodicity or Ruelle-Takens-Newhouse route to chaos. In this work, we modify the heterogeneous oscillator model of cardiac conduction system proposed in Ref. [Ryzhii E, Ryzhii M. A heterogeneous coupled oscillator model for simulation of ECG signals. Comput Meth Prog Bio 2014;117(1):40-49. doi:10.1016/j.cmpb.2014.04.009.], by including an ectopic pacemaker that stimulates the ventricular muscle to model arrhythmias. With this modification, the transition from normal rhythm to ventricular fibrillation is controlled by a single parameter. We show that this transition follows the so-called torus of quasi-periodic route to chaos, as verified by using numerical tools such as power spectrum and largest Lyapunov exponent.

Diastolic function of the nonfilling human left ventricle.

PubMed

Paulus, W J; Vantrimpont, P J; Rousseau, M F

1992-12-01

To investigate an early-diastolic left ventricular suction effect in humans, tip-micromanometer left ventricular pressure recordings were obtained in patients with mitral stenosis at the time of balloon inflations during percutaneous mitral valvuloplasty performed with a self-positioning Inoue balloon, which fits tightly in the mitral orifice. When mitral inflow was impeded in anesthetized dogs, left ventricular pressure decayed to a negative asymptote value. This negative asymptote value was consistent with an early diastolic suction effect. Tip-micromanometer left ventricular pressure recordings were obtained in 23 patients with symptomatic mitral stenosis at the time of balloon inflations during percutaneous mitral valvuloplasty performed with a self-positioning Inoue balloon. The left ventricular diastolic asymptote pressure (P(asy)) was determined in 47 nonfilling beats with a sufficiently long (greater than 200 ms) diastolic time interval (that is, the interval from minimal first derivative of left ventricular pressure to left ventricular end-diastolic pressure) and equaled 2 +/- 3 mm Hg for beats with normal intraventricular conduction and 3 +/- 2 mm Hg for beats with aberrant intraventricular conduction. Left ventricular angiography was performed in five patients during the first inflation of the Inoue balloon at the time of complete balloon expansion. Left ventricular end-diastolic volume of the nonfilling beats averaged 38 +/- 14 ml and was comparable to the left ventricular end-systolic volume (39 +/- 19 ml) measured during baseline angiography before mitral valvuloplasty. Time constants of left ventricular pressure decay were calculated on 21 nonfilling beats with a diastolic time interval greater than 200 ms, normal intraventricular conduction and peak left ventricular pressure greater than 50 mm Hg. Time constants (T0 and TBF) derived from an exponential curve fit with zero asymptote pressure and with a best-fit asymptote pressure were compared with a time constant (T(asy)) derived from an exponential curve fit with the measured diastolic left ventricular asymptote pressure. The value for T(asy) (37 +/- 9 ms) was significantly smaller than that for TBF (68 +/- 28 ms, p less than 0.001) and the value for the measured diastolic left ventricular asymptote pressure (2 +/- 4 mm Hg) was significantly larger than that for the best-fit asymptote pressure (-9 +/- 11 mm Hg, p less than 0.001). T0 (44 +/- 20 ms) was significantly (p less than 0.01) different from TBF but not from T(asy). During balloon inflation of a self-positioning Inoue balloon, left ventricular pressure decayed continuously toward a positive asymptote value and left ventricular cavity volume was comparable to the left ventricular end-systolic volume of filling beats. In these nonfilling beats, the best-fit asymptote pressure was unrelated to the measured asymptote pressure and T0 was a better measure of T(asy) than was TBF. Reduced internal myocardial restoring forces, caused by different extracellular matrix of the human heart, reduced external myocardial restoring forces caused by low coronary perfusion pressure during the balloon inflation and inward motion of the balloon-occluded mitral valve into the left ventricular cavity could explain the failure to observe significant diastolic left ventricular suction in the human heart.

Single-site ventricular pacing via the coronary sinus in patients with tricuspid valve disease.

PubMed

Noheria, Amit; van Zyl, Martin; Scott, Luis R; Srivathsan, Komandoor; Madhavan, Malini; Asirvatham, Samuel J; McLeod, Christopher J

2018-04-01

To evaluate coronary sinus single-site (CSSS) left ventricular pacing in adult patients with normal left ventricular ejection fraction (LVEF) when traditional right ventricular lead implantation is not feasible or is contraindicated. We performed a retrospective analysis of 23 patients with tricuspid valve surgery/disease who received a CSSS ventricular pacing lead to avoid crossing the tricuspid valve. Two matched control populations were obtained from patients receiving (i) conventional right ventricular single-site (RVSS) leads and (ii) coronary sinus leads for cardiac resynchronization therapy (CSCRT). Main outcomes of interest were lead stability, electrical lead parameters and change in LVEF during long-term follow-up. Successful CSSS pacing was accomplished in all 23 patients without any procedural complications. During the 5.3 ± 2.8-year follow-up 22/23 (95.7%) leads were functional with stable pacing and sensing parameters, and 1/23 (4.3%) was extracted for unrelated reasons. Compared to CSSS leads, the lead revision/abandonment was similar with RVSS leads (Hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.03, 22.0), but was higher with CSCRT leads (HR 7.41, 95% CI 1.30, 139.0). There was no difference in change in LVEF between CSSS and RVSS groups (-2.4 ± 11.0 vs. 1.5 ± 12.8, P = 0.76), but LVEF improved in CSCRT group (11.2 ± 16.5%, P = 0.002). Fluoroscopy times were longer during implantation of CSSS compared to RVSS leads (25.6 ± 24.6 min vs. 12.3 ± 18.6 min, P = 0.049). In patients with normal LVEF, single-site ventricular pacing via the coronary sinus is a feasible, safe and reliable alternative to right ventricular pacing.

Dynamic characteristic mechanism of atrial septal defect using real-time three-dimensional echocardiography and evaluation of right ventricular functions.

PubMed

Sharen, Gao-Wa; Zhang, Jun; Qin, Chuan; Lv, Qing

2017-02-01

The dynamic characteristics of the area of the atrial septal defect (ASD) were evaluated using the technique of real-time three-dimensional echocardiography (RT 3DE), the potential factors responsible for the dynamic characteristics of the area of ASD were observed, and the overall and local volume and functions of the patients with ASD were measured. RT 3DE was performed on the 27 normal controls and 28 patients with ASD. Based on the three-dimensional data workstations, the area of ASD was measured at P wave vertex, R wave vertex, T wave starting point, and T wave terminal point and in the T-P section. The right atrial volume in the same time phase of the cardiac cycle and the motion displacement distance of the tricuspid annulus in the corresponding period were measured. The measured value of the area of ASD was analyzed. The changes in the right atrial volume and the motion displacement distance of the tricuspid annulus in the normal control group and the ASD group were compared. The right ventricular ejection fractions in the normal control group and the ASD group were compared using the RT 3DE long-axis eight-plane (LA 8-plane) method. Real-time three-dimensional volume imaging was performed in the normal control group and ASD group (n=30). The right ventricular inflow tract, outflow tract, cardiac apex muscular trabecula dilatation, end-systolic volume, overall dilatation, end-systolic volume, and appropriate local and overall ejection fractions in both two groups were measured with the four-dimensional right ventricular quantitative analysis method (4D RVQ) and compared. The overall right ventricular volume and the ejection fraction measured by the LA 8-plane method and 4D RVQ were subjected to a related analysis. Dynamic changes occurred to the area of ASD in the cardiac cycle. The rules for dynamic changes in the area of ASD and the rules for changes in the right atrial volume in the cardiac cycle were consistent. The maximum value of the changes in the right atrial volume occurred in the end-systolic period when the peak of the curve appeared. The minimum value of the changes occurred in the end-systolic period and was located at the lowest point of the volume variation curve. The area variation curve for ASD and the motion variation curve for the tricuspid annulus in the cardiac cycle were the same. The displacement of the tricuspid annulus exhibited directionality. The measured values of the area of ASD at P wave vertex, R wave vertex, T wave starting point, T wave terminal point and in the T-P section were properly correlated with the right atrial volume (P<0.001). The area of ASD and the motion displacement distance of the tricuspid annulus were negatively correlated (P<0.05). The right atrial volumes in the ASD group in the cardiac cycle in various time phases increased significantly as compared with those in the normal control group (P=0.0001). The motion displacement distance of the tricuspid annulus decreased significantly in the ASD group as compared with that in the normal control group (P=0.043). The right ventricular ejection fraction in the ASD group was lower than that in the normal control group (P=0.032). The ejection fraction of the cardiac apex trabecula of the ASD patients was significantly lower than the ejection fractions of the right ventricular outflow tract and inflow tract and overall ejection fraction. The difference was statistically significant (P=0.005). The right ventricular local and overall dilatation and end-systolic volumes in the ASD group increased significantly as compared with those in the normal control group (P=0.031). The aRVEF and the overall ejection fraction decreased in the ASD group as compared with those in the normal control group (P=0.0005). The dynamic changes in the area of ASD and the motion curves for the right atrial volume and tricuspid annulus have the same dynamic characteristics. RT 3DE can be used to accurately evaluate the local and overall volume and functions of the right ventricle. The local and overall volume loads of the right ventricle in the ASD patients increase significantly as compared with those of the normal people. The right ventricular cardiac apex and the overall systolic function decrease.

[Left ventricular dysfunction measured in diabetic patients with chronic renal failure on continuous ambulatory peritoneal dialysis].

PubMed

Díaz-Arrieta, Gustavo; Mendoza-Hernández, María Elsa; Pacheco-Aranda, Erika; Rivas-Duro, Miguel; Robles-Parra, Héctor Manuel; Espinosa-Vázquez, Raúl Arturo; Hernández-Cabrera, Jorge

2010-01-01

In diabetic patients with chronic renal failure (CRF) treated with dialysis, the diastolic and systolic left ventricular dysfunction is frequent. The aim was to assess by echocardiography the prevalence of diastolic and systolic ventricular dysfunction in diabetic patients with CRF treated with continuous ambulatory peritoneal dialysis (CAPD). Sixty diabetic patients with CRF in CAPD were studied. The mean age was 54.5 +/- 12 years (27-78 years). The left ventricular filling pattern (LVFP) as a diastolic function parameter and left ventricular ejection fraction (LVEF) as a systolic function parameter were measured by transthoracic echocardiography. Descriptive statistical analysis was used. 27 (45 %) patients were women and 33 (55 %) were men. In 55 (91.7 %) left ventricular concentric hypertrophy was observed. Fifty-two patients (86.7 %) showed LVFP type I; three (5 %) had the type II; two (3.3 %) showed pseudonormal pattern and three (5 %) had a normal LVFP. The LVEF was 0.63 +/- 0.09 (CI = 0.41-0.82). Forty nine (81.7 %) patients had LVEF equal or greater than 0.55. The prevalence of diastolic left ventricular dysfunction was 95 % and the prevalence of systolic left ventricular dysfunction was 18.3%.

Is applying the same exercise-based inpatient program to normal and reduced left ventricular function patients the best strategy after coronary surgery? A focus on autonomic cardiac response.

PubMed

Mendes, Renata Gonçalves; Simões, Rodrigo Polaquini; Costa, Fernando de Souza Melo; Pantoni, Camila Bianca Falasco; Di Thommazo-Luporini, Luciana; Luzzi, Sérgio; Amaral-Neto, Othon; Arena, Ross; Catai, Aparecida Maria; Borghi-Silva, Audrey

2014-01-01

To assess whether the same exercise-based inpatient program applied to patients with normal and reduced left ventricular function (LVF) evokes a similar cardiac autonomic response after coronary artery bypass graft (CABG). Forty-four patients post-CABG, subgrouped according to normal LVF [LVFN: n = 23; left ventricular ejection fraction (LVEF) ≥ 55%] and reduced LVF (LVFR: n = 21; LVEF 35-54%), were included. All initiated the exercise protocol on post-operative day 1 (PO1), following a whole progressive program until discharge. Cardiac autonomic response was assessed by the indices of heart rate variability (HRV) at rest and during exercise (extremity range of motion and ambulation). During ambulation, lower values of HRV indices were found in the LVFR group compared with the LVFN group [standard deviation of all RR (STDRR; 6.1 ± 2.7 versus 8.9 ± 4.7 ms), baseline width of the RR histogram (TINN; 30.6 ± 14.8 versus 45.8 ± 24.9 ms), SD2 (14.8 ± 8.0 versus 21.3 ± 9.0 ms), Shannon entropy (3.6 ± 0.5 versus 3.9 ± 0.4) and correlation dimension (0.08 ± 0.2 versus 0.2 ± 0.2)]. Also, when comparing the ambulation to rest change, lower values were observed in the LVFR group for linear (STDRR, TINN, RR TRI, rMSSD) and non-linear (SD2 and correlation dimension) HRV indices (p < 0.05). On PO1, we observed only intra-group differences between rest and exercise (extremity range of motion), for mean intervals between heart beats and heart rate. For patients with LVFN, the same inpatient exercise protocol triggered a more attenuated autonomic response compared with patients with LVFR. These findings have implications as to how exercise should be prescribed according to LVF in the early stages following recovery from CABG. Implications for Rehabilitation Exercise-based inpatient program, performed by post-CABG patients who have normal left ventricular function, triggered a more attenuated cardiac autonomic response compared with patients with reduced left ventricular function. Volume of the inpatient exercises should be prescribed according to the left ventricular function in the early stages following recovery from CABG.

Left ventricular early diastolic inflow velocity and atrial ventricular plane downward velocity: useful parameters to test diastolic function in clinical practice? Diastolic parameters tested in a clinical setting.

PubMed

Winter, R; Gudmundsson, P; Ericsson, G; Willenheimer, R

2001-06-01

To study the clinical value of the colour-M-mode slope of the early diastolic left ventricular filling phase (Vp) and the early diastolic downward M-mode slope of the left atrioventricular plane displacement (EDS), compared with diastolic function assessed by traditional Doppler evaluation. In 65 consecutive patients EDS and Vp were compared with a four-degree traditional diastolic function classification, based on pulsed Doppler assessment of the early to atrial transmitral flow ratio (E/A), the E-wave deceleration time (Edt), and the systolic to diastolic (S/D) pulmonary venous inflow ratio. Vp (P=0.006) and EDS (P=0.045) were related to traditional diastolic function (Kruskal--Wallis analysis). EDS showed a trend brake between the moderate and severe diastolic dysfunction groups by traditional Doppler evaluation. Vp and EDS correlated weakly in simple linear regression analysis (r=0.33). Vp and EDS discriminated poorly between normal and highly abnormal diastolic function. Vp and EDS were significantly related to diastolic function by traditional Doppler evaluation. They were, however, not useful as single parameters of left ventricular diastolic function due to a small difference between normal and highly abnormal values, allowing for little between-measurement variability. Consequently, these methods for the evaluation of left ventricular diastolic function do not add significantly to traditional Doppler evaluation.

Potential fields on the ventricular surface of the exposed dog heart during normal excitation.

PubMed

Arisi, G; Macchi, E; Baruffi, S; Spaggiari, S; Taccardi, B

1983-06-01

We studied the normal spread of excitation on the anterior and posterior ventricular surface of open-chest dogs by recording unipolar electrograms from an array of 1124 electrodes spaced 2 mm apart. The array had the shape of the ventricular surface of the heart. The electrograms were processed by a computer and displayed as epicardial equipotential maps at 1-msec intervals. Isochrone maps also were drawn. Several new features of epicardial potential fields were identified: (1) a high number of breakthrough points; (2) the topography, apparent widths, velocities of the wavefronts and the related potential drop; (3) the topography of positive potential peaks in relation to the wavefronts. Fifteen to 24 breakthrough points were located on the anterior, and 10 to 13 on the posterior ventricular surface. Some were in previously described locations and many others in new locations. Specifically, 3 to 5 breakthrough points appeared close to the atrioventricular groove on the anterior right ventricle and 2 to 4 on the posterior heart aspect; these basal breakthrough points appeared when a large portion of ventricular surface was still unexcited. Due to the presence of numerous breakthrough points on the anterior and posterior aspect of the heart which had not previously been described, the spread of excitation on the ventricular surface was "mosaic-like," with activation wavefronts spreading in all directions, rather than radially from the two breakthrough points, as traditionally described. The positive potential peaks which lay ahead of the expanding wavefronts moved along preferential directions which were probably related to the myocardial fiber direction.

Electrical Substrate Elimination in 135 Consecutive Patients With Brugada Syndrome.

PubMed

Pappone, Carlo; Brugada, Josep; Vicedomini, Gabriele; Ciconte, Giuseppe; Manguso, Francesco; Saviano, Massimo; Vitale, Raffaele; Cuko, Amarild; Giannelli, Luigi; Calovic, Zarko; Conti, Manuel; Pozzi, Paolo; Natalizia, Andrea; Crisà, Simonetta; Borrelli, Valeria; Brugada, Ramon; Sarquella-Brugada, Georgia; Guazzi, Marco; Frigiola, Alessandro; Menicanti, Lorenzo; Santinelli, Vincenzo

2017-05-01

There is emerging evidence that localization and elimination of abnormal electric activity in the epicardial right ventricular outflow tract may be beneficial in patients with Brugada syndrome. A total of 135 symptomatic Brugada syndrome patients having implantable cardiac defibrillator were enrolled: 63 (group 1) having documented ventricular tachycardia (VT)/ventricular fibrillation (VF) and Brugada syndrome-related symptoms, and 72 (group 2) having inducible VT/VF without ECG documentation at the time of symptoms. About 27 patients of group 1 experienced multiple implantable cardiac defibrillator shocks for recurrent VT/VF episodes. Three-dimensional maps before and after ajmaline determined the arrhythmogenic electrophysiological substrate (AES) as characterized by prolonged fragmented ventricular potentials. Primary end point was identification and elimination of AES leading to ECG pattern normalization and VT/VF noninducibility. Extensive areas of AES were found in the right ventricle epicardium, which were wider in group 1 ( P =0.007). AES increased after ajmaline in both groups ( P <0.001) and was larger in men ( P =0.008). The increase of type-1 ST-segment elevation correlated with AES expansion ( r =0.682, P <0.001). Radiofrequency ablation eliminated AES leading to ECG normalization and VT/VF noninducibility in all patients. During a median follow-up of 10 months, the ECG remained normal even after ajmaline in all except 2 patients who underwent a repeated effective procedure for recurrent VF. In Brugada syndrome, AES is commonly located in the right ventricle epicardium and ajmaline exposes its extent and distribution, which is correlated with the degree of coved ST-elevation. AES elimination by radiofrequency ablation results in ECG normalization and VT/VF noninducibility. Substrate-based ablation is effective in potentially eliminating the arrhythmic consequences of this genetic disease. URL: https://clinicaltrials.gov. Unique identifier: NCT02641431. © 2017 American Heart Association, Inc.

Assessment of right ventricular function with nonimaging first pass ventriculography and comparison of results with gamma camera studies.

PubMed

Zhang, Z; Liu, X J; Liu, Y Z; Lu, P; Crawley, J C; Lahiri, A

1990-08-01

A new technique has been developed for measuring right ventricular function by nonimaging first pass ventriculography. The right ventricular ejection fraction (RVEF) obtained by non-imaging first pass ventriculography was compared with that obtained by gamma camera first pass and equilibrium ventriculography. The data has demonstrated that the correlation of RVEFs obtained by the nonimaging nuclear cardiac probe and by gamma camera first pass ventriculography in 15 subjects was comparable (r = 0.93). There was also a good correlation between RVEFs obtained by the nonimaging nuclear probe and by equilibrium gated blood pool studies in 33 subjects (r = 0.89). RVEF was significantly reduced in 15 patients with right ventricular and/or inferior myocardial infarction compared to normal subjects (28 +/- 9% v. 45 +/- 9%). The data suggests that nonimaging probes may be used for assessing right ventricular function accurately.

Clinical applications of a quantitative analysis of regional lift ventricular wall motion

NASA Technical Reports Server (NTRS)

Leighton, R. F.; Rich, J. M.; Pollack, M. E.; Altieri, P. I.

1975-01-01

Observations were summarized which may have clinical application. These were obtained from a quantitative analysis of wall motion that was used to detect both hypokinesis and tardokinesis in left ventricular cineangiograms. The method was based on statistical comparisons with normal values for regional wall motion derived from the cineangiograms of patients who were found not to have heart disease.

Changes in ventricular function during emotional stress and cold exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiess, M.C.; Moore, R.A.; Dimsdale, J.

1984-01-01

Patients with cardiac disease frequently develop symptoms with emotional stress or cold exposure. To investigate the effects of these stresses in normal subjects, an ambulatory ventricular function monitor (VEST) (previously reported to measure EFs which correlate well with gamma camera measurements) was employed to record sequential 2 minute time activity curves from the left ventricles of 6 healthy men (ages 19-24) during a control period and during a 30 minute stress interview with a psychiatrist. Four of the subjects were also monitored in a cold room (1/sup 0/C) for 20 min. In addition to the left ventricular time-activity curve, heartmore » rate (HR), and BP (cuff) were recorded. All subjects had increases in HR, BP and EF during the stress interview. Cold, however, produced decreases in HR and EF and an increase in BP. The results (mean +- SD) are tabulated. End-systolic and end-diastolic counts and hence volume decreased during the interview and increased during cold exposure. The results suggest that (1) ambulatory changes in ventricular function can be measured with the VEST, and (2) significant changes in cardiovascular physiology are seen in normal subjects during a stress interview and exposure to cold.« less

Left bundle branch block, an old-new entity.

PubMed

Breithardt, Günter; Breithardt, Ole-Alexander

2012-04-01

Left bundle branch block (LBBB) is generally associated with a poorer prognosis in comparison to normal intraventricular conduction, but also in comparison to right bundle branch block which is generally considered to be benign in the absence of an underlying cardiac disorder like congenital heart disease. LBBB may be the first manifestation of a more diffuse myocardial disease. The typical surface ECG feature of LBBB is a prolongation of QRS above 0.11 s in combination with a delay of the intrinsic deflection in leads V5 and V6 of more than 60 ms and no septal q waves in leads I, V5, and V6 due to the abnormal septal activation from right to left. LBBB may induce abnormalities in left ventricular performance due to abnormal asynchronous contraction patterns which can be compensated by biventricular pacing (resynchronization therapy). Asynchronous electrical activation of the ventricles causes regional differences in workload which may lead to asymmetric hypertrophy and left ventricular dilatation, especially due to increased wall mass in late-activated regions, which may aggravate preexisting left ventricular pumping performance or even induce it. Of special interest are patients with LBBB and normal left ventricular dimensions and normal ejection fraction at rest but who may present with an abnormal increase in pulmonary artery pressure during exercise, production of lactate during high-rate pacing, signs of ischemia on myocardial scintigrams (but no coronary artery narrowing), and abnormal ultrastructural findings on myocardial biopsy. For this entity, the term latent cardiomyopathy had been suggested previously.

Correlation between lumbo-ventricular perfusion and MRI-CSF flow studies in idiopathic normal pressure hydrocephalus.

PubMed

Hakim, R; Black, P M

1998-01-01

After the initial description of normal pressure hydrocephalus (NPH) and its clinical triad, there has been a continuous interest from clinicians and researchers to set different diagnostic criteria that would make the selection of candidates for shunt surgery easier and more precise. A preliminary group of 12 patients was given a diagnosis of idiopathic normal pressure hydrocephalus by clinical and radiologic criteria. Each patient underwent two different tests: a magnetic resonance imaging-cerebrospinal fluid (MRI-CSF) flow study and a lumbo-ventricular perfusion test. The purpose was to compare the correlation of the results obtained with these tests and the clinical results obtained after CSF diversion. Eleven patients were given shunts and one was managed with lumbar punctures. One year after treatment, 10 of the 12 patients had improved with good results. The MRI-CSF flow studies were reliable in six patients; there were five false negatives and one false positive. The lumbo-ventricular perfusion test showed reliability in nine patients; there were two false negatives and one false positive. In only three patients were the results of both of these tests in accordance with the outcome. Even though there are few patients in this study so far, the data suggests that at the present time the most predictive guides for the diagnosis of NPH and its outcome after shunting are the clinical criteria and the radiological findings in computed tomography (CT) and/or MRI rather than lumbo-ventricular perfusion and CSF flow studies.

Tissue Doppler Imaging can be useful to distinguish pathological from physiological left ventricular hypertrophy: a study in master athletes and mild hypertensive subjects

PubMed Central

Galanti, Giorgio; Toncelli, Loira; Del Furia, Francesca; Stefani, Laura; Cappelli, Brunello; De Luca, Alessio; Vono, Maria Concetta Roberta

2009-01-01

Background Transthoracic echocardiography left ventricular wall thickness is often increased in master athletes and it results by intense physical training. Left Ventricular Hypertrophy can also be due to a constant pressure overload. Conventional Pulsed Wave (PW) Doppler analysis of diastolic function sometimes fails to distinguish physiological from pathological LVH. The aim of this study is to evaluate the role of Pulsed Wave Tissue Doppler Imaging in differentiating pathological from physiological LVH in the middle-aged population. Methods we selected a group of 80 master athletes, a group of 80 sedentary subjects with essential hypertension and an apparent normal diastolic function at standard PW Doppler analysis. The two groups were comparable for increased left ventricular wall thickness and mass index (134.4 ± 19.7 vs 134.5 ± 22.1 gr/m2; p > .05). Diastolic function indexes using the PW technique were in the normal range for both. Results Pulsed Wave TDI study of diastolic function immediately distinguished the two groups. While in master athletes the diastolic TDI-derived parameters remained within normal range (E' 9.4 ± 3.1 cm/sec; E/E' 7.8 ± 2.1), in the hypertensive group these parameters were found to be constantly altered, with mean values and variation ranges always outside normal validated limits (E' 7.2 ± 2.4 cm/sec; E/E' 10.6 ± 3.2), and with E' and E/E' statistically different in the two groups (p < .001). Conclusion Our study showed that the TDI technique can be an easy and validated method to assess diastolic function in differentiating normal from pseudonormal diastolic patterns and it can distinguish physiological from pathological LVH emphasizing the eligibility certification required by legal medical legislation as in Italy. PMID:19845938

Comparison of stroke work between repaired tetralogy of Fallot and normal right ventricular physiologies.

PubMed

Lee, Namheon; Das, Ashish; Banerjee, Rupak K; Gottliebson, William M

2013-01-01

Adult patients who underwent tetralogy of Fallot repair surgery (rTOF) confront life-threatening ailments due to right ventricular (RV) myocardial dysfunction. Pulmonary valve replacement (PVR) needs to be performed to restore the deteriorating RV function. Determination of correct timing to perform PVR in an rTOF patient remains subjective, due to the unavailability of quantifiable clinical diagnostic parameters. The objective of this study is to evaluate the possibility of using RV body surface area (BSA)-indexed stroke work (SW(I)) to quantify RV inefficiency in TOF patients. We hypothesized that RV SW(I) required to push blood to the lungs in rTOF patients is significantly higher than that of normal subjects. Seven patients with rTOF pathophysiology and eight controls with normal RV physiology were registered for this study. Right ventricular volume and pressure were measured using cardiac magnetic resonance imaging and catheterization, respectively. Statistical analysis was performed to quantify the difference in SW(I) between the RV of the rTOF and control groups. Right ventricular SW(I) in rTOF patients (0.176 ± 0.055 J/m(2)) was significantly higher by 93.4% (P = 0.0026) than that of controls (0.091 ± 0.030 J/m(2)). Further, rTOF patients were found to have significantly higher (P < 0.05) BSA normalized RV end-systolic volume, end-systolic pressure, and regurgitation fraction than control subjects. Ejection fraction and peak ejection rate of rTOF patients were significantly lower (P < 0.05) than those of controls. Patients with rTOF pathophysiology had significantly higher RV SW(I) compared with subjects with normal RV physiology. Therefore, RV SW(I) may be useful to quantify RV inefficiency in rTOF patients along with currently used clinical end points such as RV volume, pressure, regurgitation fraction, and ejection fraction.

Right Ventricular Thrombosis Combined With Fetal Death and Acrocyanosis in Pregnancy.

PubMed

Sabzi, Feridoun; Heidari, Aghigh

2017-07-01

Prepartum or postpartum right ventricular thrombosis (RVT) is an exceedingly rare and potentially lethal phenomenon in pregnancy. We here report a case of a pregnant patient with near term pregnancy admitted for dyspnea, amniotic fluids discharge and labor pain in a gynecology center that an eight-month dead fetus was diagnosed and delivered vaginally by induction. A post delivery period was complicated by aggravation of her dyspnea and pleuritic chest pain that she referred for further evaluation in our cardiac center. Physical exam revealed normal head and neck exam, and history taking revealed that her fetus had intra-uterine growth failure as reported by her gynecologist. Chest exam except to left lung crackle was normal. Lower and upper left extremities were normal. However, acrocyanosis was found in tips of 4 and 5th right-hand digits. Chest x-ray revealed some linear consolidation in left lower lung lobes, and the precordial exam was normal. ECG was normal. Post delivery transthoracic echocardiography (TEE) showed a 1.5×1.5 cm mobile right ventricular clot. C-T angiography revealed obstruction of left upper lung pulmonary artery branches. Complete thrombophilia assay showed the presence of high titer of antiphospholipid, anticardiolipin antibody, and β1 glycoprotein antibody. However, others test were normal. The patient was scheduled for cardiac surgery, and her hemodynamic was monitored by left radial artery line and central pressure venous line, and thrombus was removed from the right ventricle (RV), and subsequent anticoagulation therapy constituted. Six-month follow-up revealed no recurrence of thrombus and recovery of patient's symptoms.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Congenital left-sided heart obstruction

PubMed Central

Carr, Michelle; Curtis, Stephanie; Marek, Jan

2018-01-01

Congenital obstruction of the left ventricular outflow tract remains a significant problem and multilevel obstruction can often coexist. Obstruction can take several morphological forms and may involve the subvalvar, valvar or supravalvar portion of the aortic valve complex. Congenital valvar stenosis presenting in the neonatal period represents a spectrum of disorders ranging from the hypoplastic left heart syndrome to almost normal hearts. Treatment options vary dependent on the severity of the left ventricular outflow tract obstruction (LVOTO) and the variable degree of left ventricular hypoplasia as well as the associated lesions such as arch hypoplasia and coarctation. PMID:29681546

Relation of N-Terminal Pro-B-Type Natriuretic Peptide and Left Ventricular Diastolic Function to Exercise Tolerance in Patients With Significant Valvular Heart Disease and Normal Left Ventricular Systolic Function.

PubMed

Hwang, Ji-Won; Park, Sung-Ji; Cho, Eun Jeong; Kim, Eun Kyoung; Lee, Ga Yeon; Chang, Sung-A; Choi, Jin-Oh; Lee, Sang-Chol; Park, Seung Woo

2017-06-01

An association between N-terminal prohormone brain natriuretic peptide (NT-proBNP) and exercise tolerance in patients with valvular heart disease (VHD) has been suggested; however, there are few data available regarding this relation. The aim of this study is to evaluate the correlation between exercise tolerance and NT-proBNP in patients with asymptomatic or mildly symptomatic significant VHD and normal left ventricular ejection fraction (LV EF). A total of 96 patients with asymptomatic or mildly symptomatic VHD and normal LV EF (≥50%) underwent cardiopulmonary exercise echocardiography. NT-proBNP levels were determined at baseline and after exercise in 3 hours. Patients were divided in 2 groups based on lower (<26 ml/kg/min, n = 47) or higher (≥26 ml/kg/min, n = 49) peak oxygen consumption (VO 2 ) as a representation of exercise tolerance. In the 2 groups, after adjusting for age and gender, the NT-proBNP level after exercise in 3 hours, left atrial volume index before exercise, right ventricular systolic pressure before exercise, E velocity after exercise, and E/e' ratio after exercise varied significantly. In addition, peak VO 2 was inversely related to NT-proBNP before (r = -0.352, p <0.001) and after exercise (r = -0.351, p <0.001). The NT-proBNP level before exercise was directly related to the left atrial volume index, E/e' ratio, and right ventricular systolic pressure before and after exercise. NT-proBNP after exercise was also directly related to the same parameters. NT-proBNP levels both before and after exercise were higher in the group with lower exercise tolerance. In conclusion, through the correlation among exercise tolerance, NT-proBNP, and parameters of diastolic dysfunction, we demonstrated that diastolic dysfunction and NT-proBNP could predict exercise tolerance in patients with significant VHD and normal LV EF. Copyright © 2017 Elsevier Inc. All rights reserved.

Internal associations and dynamic expression of c-kit and nanog genes in ventricular remodelling induced by adriamycin.

PubMed

Liu, Zhen; Li, Shuo; Liu, Lingling; Guo, Zhikun; Wang, Pengfei

2016-09-01

The present study aimed to investigate the dynamic expression of the c-kit and nanog genes in rats with left ventricular remodelling induced by adriamycin (ADR), and explore its internal association and mechanism of action. Sprague-Dawley male rats were randomly divided into a normal control group and a heart failure model group. Heart failure was induced by a single intraperitoneal injection of ADR (4 mg/kg) weekly for six weeks. The normal control group was given the same amount of saline. At the eighth week, rat cardiac function was examined to demonstrate the formation of heart failure. The rat hearts were harvested frozen and sectioned, and the expression levels of the nanog and c-kit genes in the myocardial tissue samples were detected using immunohistochemistry, immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). Hematoxylin and eosin staining demonstrated various pathological changes in the myocardial cells in the heart failure model group, whereas myocardial infarction was not observed in the normal control group. Immunohistochemistry and immunofluorescence demonstrated that nanog-positive cells were predominantly expressed in the vascular endothelium, with a few myocardial cells and stem cells in normal myocardium. The expression levels of c-kit and nanog in the myocardium of the rats with heart failure decreased significantly. c-kit-positive cells clustered together in the epicardium and its vicinity, and c-kit expression significantly decreased in the myocardium of rats with heart failure, as compared with normal rats. In both groups, some cells co-expressed both the c-kit and nanog genes. The RT-PCR results demonstrated that the expression levels of the two genes in the heart failure model group were significantly lower compared with those in the normal control group (P<0.05). In conclusion, the c-kit- and nanog-positive stem cells decreased in the myocardium of the rats with left ventricular remodelling induced by ADR. Their abnormal expression was significantly correlated with left ventricular remodelling, thereby indicating an internal association (influences of two indexes in the experimental group and control group) between them.

Left ventricular dysfunction after closure of large patent ductus arteriosus.

PubMed

Galal, M Omar; Amin, Mohamed; Hussein, Arif; Kouatli, Amjad; Al-Ata, Jameel; Jamjoom, Ahmed

2005-03-01

Changes in left ventricular dimensions and performance were studied in 43 patients after transcatheter occlusion or surgical ligation of patent ductus arteriosus. The patients were assigned to 2 groups based on their ductal diameter: >/= 3.1 mm to group A (n = 27) and

The helical ventricular myocardial band: global, three-dimensional, functional architecture of the ventricular myocardium.

PubMed

Kocica, Mladen J; Corno, Antonio F; Carreras-Costa, Francesc; Ballester-Rodes, Manel; Moghbel, Mark C; Cueva, Clotario N C; Lackovic, Vesna; Kanjuh, Vladimir I; Torrent-Guasp, Francisco

2006-04-01

We are currently witnessing the advent of new diagnostic tools and therapies for heart diseases, but, without serious scientific consensus on fundamental questions about normal and diseased heart structure and function. During the last decade, three successive, international, multidisciplinary symposia were organized in order to setup fundamental research principles, which would allow us to make a significant step forward in understanding heart structure and function. Helical ventricular myocardial band of Torrent-Guasp is the revolutionary new concept in understanding global, three-dimensional, functional architecture of the ventricular myocardium. This concept defines the principal, cumulative vectors, integrating the tissue architecture (i.e. form) and net forces developed (i.e. function) within the ventricular mass. Here we expose the compendium of Torrent-Guasp's half-century long functional anatomical investigations in the light of ongoing efforts to define the integrative approach, which would lead to new understanding of the ventricular form and function by linking across multiple scales of biological organization, as defined in ongoing Physiome project. Helical ventricular myocardial band of Torrent-Guasp may also, hopefully, allow overcoming some difficulties encountered in contemporary efforts to create a comprehensive mathematical model of the heart.

Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rakovec, P.; Kranjec, I.; Fettich, J.J.

1985-01-01

Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combinedmore » electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates.« less

5-Fluorouracil cardiotoxicity: reversible left ventricular systolic dysfunction with early detection.

PubMed

Iskandar, Muhammad Zaid; Quasem, Wahid; El-Omar, Magdi

2015-05-02

A 33-year-old man presented to hospital with acute shortness of breath and evolving ST segment changes on ECG 3 days following a cycle of 5-fluorouracil (5-FU) for colon cancer. Despite no cardiac history, subsequent echocardiogram showed severe left ventricular systolic dysfunction. The patient was initially treated with heart failure medications and his coronary angiogram was normal. Chemotherapy was stopped and he was started on nitrates and calcium channel blockers. A repeat echocardiogram and cardiac MRI a week later showed complete resolution of his left ventricular dysfunction and he was discharged home. This case report summarises 5-FU cardiotoxicity, and emphasises the importance of early recognition and correct treatment, as left ventricular systolic dysfunction in this context is potentially reversible. 2015 BMJ Publishing Group Ltd.

5-Fluorouracil cardiotoxicity: reversible left ventricular systolic dysfunction with early detection

PubMed Central

Iskandar, Muhammad Zaid; Quasem, Wahid; El-Omar, Magdi

2015-01-01

A 33-year-old man presented to hospital with acute shortness of breath and evolving ST segment changes on ECG 3 days following a cycle of 5-fluorouracil (5-FU) for colon cancer. Despite no cardiac history, subsequent echocardiogram showed severe left ventricular systolic dysfunction. The patient was initially treated with heart failure medications and his coronary angiogram was normal. Chemotherapy was stopped and he was started on nitrates and calcium channel blockers. A repeat echocardiogram and cardiac MRI a week later showed complete resolution of his left ventricular dysfunction and he was discharged home. This case report summarises 5-FU cardiotoxicity, and emphasises the importance of early recognition and correct treatment, as left ventricular systolic dysfunction in this context is potentially reversible. PMID:25935919

Three-dimensional echocardiographic measurements using automated quantification software for big data processing.

PubMed

Feng, Cheng; Chen, Lixin; Li, Jian; Wang, Jiangtao; Dong, Fajin; Xu, Jinfeng

2017-01-01

To compare a full-automated software to quantify 3D transthoracic echocardiography namely, 3DE-HM (three-dimensional echocardiography HeartModel, Philips Healthcare) with the traditional manual quantitative method (3DE-manual) for assessing volumes of left atrial and ventricular volumes, and left ventricular ejection fraction (LVEF). 3D full volume images acquired from 156 subjects were collected and divided into 3 groups, which include 70 normal control cases (Group A), 17 patients with left ventricular remodeling after acute myocardial infarction (AMI) (Group B), and 69 patients with left atrial remodeling secondary to hypertension (Group C). The 3DE-HM method was used to quantify left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left atrial end-systolic volume (LAESV), and left ventricular ejection fraction (LVEF), respectively. The results were compared with those obtained with the 3DE-manual method for correlation and consistency analyses. The reproducibility of the 3DE-HM method was also evaluated. There was a high correlation between LVEDV, LVESV, LAESV and LVEF values obtained with the 3DE-HM method and those obtained using the 3DE-manual method (r = 0.72 to 0.97). The correlation was strongest for Group B, patients with left ventricular remodeling post-AMI also demonstrated the greatest degree of morphologic changes. There was a significant difference in all parameters measured with the 3DE-HM method in different groups (P < 0.05). The difference in the measurements of LVEDV and LVESV between the two methods was greatest in patients in Group B compared with patients with hypertension-induced left ventricular remodeling (Group C) and in normal controls (Group A) (P < 0.05). Lastly, the difference in the measurement of LAESV between the two methods was greater in patients with hypertension-induced left ventricular remodeling (Group C) than that in the control group (Group A) (P < 0.05). The post-processing time of the 3DE-HM data was significantly shorter than that using the 3DE-manual method (P < 0.05). There was no significant variability in repeated measurements at different time points using the 3DE-HM method either between subjects in different groups or within the same subject. 3DE-HM is a quick and feasible method for left ventricular quantification and is clinically applicable for evaluating patients with left atrial and left ventricular remodeling.

Implications of persistent prehypertension for ageing-related changes in left ventricular geometry and function: the MONICA/KORA Augsburg study.

PubMed

Markus, Marcello Ricardo Paulista; Stritzke, Jan; Lieb, Wolfgang; Mayer, Björn; Luchner, Andreas; Döring, Angela; Keil, Ulrich; Hense, Hans-Werner; Schunkert, Heribert

2008-10-01

It is unclear whether persistent prehypertension causes structural or functional alterations of the heart. We examined echocardiographic data of 1005 adults from a population-based survey at baseline in 1994/1995 and at follow-up in 2004/2005. We compared individuals who had either persistently normal (<120 mmHg systolic and <80 mmHg diastolic, n = 142) or prehypertensive blood pressure (120-139 mmHg or 80-89 mmHg, n = 119) at both examinations using multivariate regression modeling. Over 10 years, left ventricular end-diastolic diameters were stable and did not differ between the two groups. However, the prehypertensive blood pressure group displayed more pronounced ageing-related increases of left ventricular wall thickness (+4.7 versus +11.9%, P < 0.001) and left ventricular mass (+8.6 versus +15.7%, P = 0.006). Prehypertension was associated with a raised incidence of left ventricular concentric remodeling (adjusted odds ratio 10.7, 95% confidence interval 2.82-40.4) and left ventricular hypertrophy (adjusted odds ratio 5.33, 1.58-17.9). The ratio of early and late diastolic peak transmitral flow velocities (E/A) decreased by 7.7% in the normal blood pressure versus 15.7% in the prehypertensive blood pressure group (P = 0.003) and at follow-up the ratio of early diastolic peak transmitral flow and early diastolic peak myocardial relaxation velocities (E/EM) was higher (9.1 versus 8.5, P = 0.031) and left atrial size was larger (36.5 versus 35.3 mm, P = 0.024) in the prehypertensive blood pressure group. Finally, the adjusted odds ratio for incident diastolic dysfunction was 2.52 (1.01-6.31) for the prehypertensive blood pressure group. Persistent prehypertension accelerates the development of hypertrophy and diastolic dysfunction of the heart.

Epinephrine and left atrial and left ventricular diastolic function decrease in normal subjects.

PubMed

Fuenmayor, Abdel J; Solórzano, Moisés I; Gómez, Luisangelly

2016-10-01

We assessed the effect of epinephrine over left atrial and left ventricular diastolic function in subjects without structural heart disease. Twenty-seven, 34.6±17.2year-old patients without structural heart disease were included. Intravenous epinephrine (50 to 100ng/kg/min) was infused. Left atrial and ventricular functions were evaluated by means of echocardiography before and during the epinephrine infusion. No complications were observed. Significant increases in heart rate and systolic blood pressure were recorded. Both left atrial (minimal and maximal) volumes increased but increase in the minimal volume was more pronounced, and the ejection fraction diminished. Left atrial expansion index decreased and the fraction of left ventricular inflow volume resulting from atrial contraction increased. Two patients displayed abnormal left ventricular diastolic function. During epinephrine infusion, E/A and e' decreased, and isovolumetric relaxation time increased. In this group of young adults without structural heart disease, epinephrine infusion was safe, did not produce any complications, and induced a small but significant decrease in left atrial function and left ventricular diastolic function. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Recurrent syncope attributed to left main coronary artery severe stenosis.

PubMed

Li, Min; Zheng, Xinyi; Liu, Hua; Liu, Yujie

2015-01-01

Patients with acute coronary syndrome (ACS) rarely manifest as recurrent syncope due to malignant ventricular arrhythmia. We report a case of a 56-year-old Chinese male with complaints of paroxysmal chest burning sensation and distress for 2 weeks as well as loss of consciousness for 3 days. The electrocardiogram (ECG) revealed paroxysmal multimorphologic ventricular tachycardia during attack and normal heart rhythm during intervals. Coronary angiograph showed 90% stenosis in left main coronary artery and 80% stenosis in anterior descending artery. Two stents sized 4.0∗18 mm and 2.75∗18 mm were placed at left main coronary artery and anterior descending artery, respectively, during percutaneous coronary intervention (PCI). The patient was discharged and never had ventricular arrhythmia again during a 3-month follow-up since the PCI. This indicated that ventricular tachycardia was correlated with persistent severe myocardial ischemia. Coronary vasospasm was highly suspected to be the reason of the sudden attack and acute exacerbation. PCI is recommended in patients with both severe coronary artery stenosis and ventricular arrhythmia. Removing myocardial ischemia may stop or relieve ventricular arrhythmia and prevent cardiac arrest.

Prevalence and Prognostic Significance of Right Ventricular Systolic Dysfunction in Patients Undergoing Transcatheter Aortic Valve Implantation.

PubMed

Lindsay, Alistair C; Harron, Katie; Jabbour, Richard J; Kanyal, Ritesh; Snow, Thomas M; Sawhney, Paramvir; Alpendurada, Francisco; Roughton, Michael; Pennell, Dudley J; Duncan, Alison; Di Mario, Carlo; Davies, Simon W; Mohiaddin, Raad H; Moat, Neil E

2016-07-01

Cardiovascular magnetic resonance (CMR) can provide important structural information in patients undergoing transcatheter aortic valve implantation. Although CMR is considered the standard of reference for measuring ventricular volumes and mass, the relationship between CMR findings of right ventricular (RV) function and outcomes after transcatheter aortic valve implantation has not previously been reported. A total of 190 patients underwent 1.5 Tesla CMR before transcatheter aortic valve implantation. Steady-state free precession sequences were used for aortic valve planimetry and to assess ventricular volumes and mass. Semiautomated image analysis was performed by 2 specialist reviewers blinded to patient treatment. Patient follow-up was obtained from the Office of National Statistics mortality database. The median age was 81.0 (interquartile range, 74.9-85.5) years; 50.0% were women. Impaired RV function (RV ejection fraction ≤50%) was present in 45 (23.7%) patients. Patients with RV dysfunction had poorer left ventricular ejection fractions (42% versus 69%), higher indexed left ventricular end-systolic volumes (96 versus 40 mL), and greater indexed left ventricular mass (101 versus 85 g/m(2); P<0.01 for all) than those with normal RV function. Median follow-up was 850 days; 21 of 45 (46.7%) patients with RV dysfunction died, compared with 43 of 145 (29.7%) patients with normal RV function (P=0.035). After adjustment for significant baseline variables, both RV ejection fraction ≤50% (hazard ratio, 2.12; P=0.017) and indexed aortic valve area (hazard ratio, 4.16; P=0.025) were independently associated with survival. RV function, measured on preprocedural CMR, is an independent predictor of mortality after transcatheter aortic valve implantation. CMR assessment of RV function may be important in the risk stratification of patients undergoing transcatheter aortic valve implantation. © 2016 American Heart Association, Inc.

Fatigue as Presenting Symptom and a High Burden of Premature Ventricular Contractions Are Independently Associated With Increased Ventricular Wall Stress in Patients With Normal Left Ventricular Function.

PubMed

van Huls van Taxis, Carine F B; Piers, Sebastiaan R D; de Riva Silva, Marta; Dekkers, Olaf M; Pijnappels, Daniël A; Schalij, Martin J; Wijnmaalen, Adrianus P; Zeppenfeld, Katja

2015-12-01

High idiopathic premature ventricular contractions (PVC) burden has been associated with PVC-induced cardiomyopathy. Patients may be symptomatic before left ventricular (LV) dysfunction develops. N-terminal pro-B-type natriuretic peptide (NT-proBNP) and circumferential end-systolic wall stress (cESS) on echocardiography are markers for increased ventricular wall stress. This study aimed to evaluate the relation between presenting symptoms, PVC burden, and increased ventricular wall stress in patients with frequent PVCs and preserved LV function. Eighty-three patients (41 men; 49±15 years) with idiopathic PVCs and normal LV function referred for PVC ablation were included. Type of symptoms (palpitations, fatigue, and [near-]syncope), PVC burden on 24-hour Holter, NT-proBNP levels, and cESS on echocardiography were assessed before and 3 months after ablation. Sustained successful ablation was defined as ≥80% PVC burden reduction during follow-up. Patients were symptomatic for 24 months (Q1-Q3, 16-60); 73% reported palpitations, 47% fatigue, and 30% (near-)syncope. Baseline PVC burden was 23±13%, median NT-proBNP 92 pg/mL (Q1-Q3 50-156), and cESS 143±35 kdyne/cm(2). Fatigue was associated with higher baseline NT-proBNP and cESS (P<0.001, P=0.011, respectively). After sustained successful ablation, achieved in 81%, NT-proBNP and cESS decreased significantly (P<0.001 and P=0.036, respectively). Fatigue was independently associated with a significantly larger reduction in NT-proBNP. In patients with nonsuccessful ablation, NT-proBNP and cESS remained unchanged. In patients with frequent PVCs and preserved LV function, fatigue was associated with higher baseline NT-proBNP and cESS, and with a significantly larger reduction in NT-proBNP after sustained successful ablation. These findings support a link between fatigue and PVC-induced increased ventricular wall stress, despite preserved LV function. © 2015 American Heart Association, Inc.

Dual-dye optical mapping after myocardial infarction: does the site of ventricular stimulation alter the properties of electrical propagation?

PubMed

Saba, Samir; Mathier, Michael A; Mehdi, Haider; Liu, Tong; Choi, Bum-Rak; London, Barry; Salama, Guy

2008-02-01

Myocardial infarction (MI) disrupts electrical conduction in affected ventricular areas. We investigated the effect of MI on the regional voltage and calcium (Ca) signals and their propagation properties, with special attention to the effect of the site of ventricular pacing on these properties. New Zealand White rabbits were divided into four study groups: sham-operated (C, n = 6), MI with no pacing (MI, n = 7), MI with right ventricular pacing (MI + RV, n = 6), and MI with BIV pacing (MI + BIV, n = 7). At 4 weeks, hearts were excised, perfused, and optically mapped. As previously shown, systolic and diastolic dilation of the LV were prevented by BIV pacing, as was the reduction in LV fractional shortening. Four weeks after MI, optical mapping revealed markedly reduced action potential amplitudes and conduction velocities (CV) in MI zones, and these increased gradually in the border zone and normal myocardial areas. Also, Ca transients were absent in the infarcted areas and increased gradually 3-5 mm from the border of the normal zone. Neither BIV nor RV pacing affected these findings in any of the MI, border, or normal zones. MI has profound effects on the regional electrical and Ca signals and on their propagation properties in this rabbit model. The absence of differences in these parameters by study group suggests that altering the properties of myocardial electrical conduction and Ca signaling are unlikely mechanisms by which BIV pacing confers its benefits. Further studies into the regional, cellular, and molecular benefits of BIV pacing are therefore warranted.

Hyperdynamic left ventricular ejection fraction in the intensive care unit.

PubMed

Paonessa, Joseph R; Brennan, Thomas; Pimentel, Marco; Steinhaus, Daniel; Feng, Mengling; Celi, Leo Anthony

2015-08-07

Limited information exists on the etiology, prevalence, and significance of hyperdynamic left ventricular ejection fraction (HDLVEF) in the intensive care unit (ICU). Our aim in the present study was to compare characteristics and outcomes of patients with HDLVEF with those of patients with normal left ventricular ejection fraction in the ICU using a large, public, deidentified critical care database. We conducted a longitudinal, single-center, retrospective cohort study of adult patients who underwent echocardiography during a medical or surgical ICU admission at the Beth Israel Deaconess Medical Center using the Multiparameter Intelligent Monitoring in Intensive Care II database. The final cohort had 2867 patients, of whom 324 had HDLVEF, defined as an ejection fraction >70%. Patients with an ejection fraction <55% were excluded. Compared with critically ill patients with normal left ventricular ejection fraction, the finding of HDLVEF in critically ill patients was associated with female sex, increased age, and the diagnoses of hypertension and cancer. Patients with HDLVEF had increased 28-day mortality compared with those with normal ejection fraction in multivariate logistic regression analysis adjusted for age, sex, Sequential Organ Failure Assessment score, Elixhauser score for comorbidities, vasopressor use, and mechanical ventilation use (odds ratio 1.38, 95% confidence interval 1.039-1.842, p =0.02). The presence of HDLVEF portended increased 28-day mortality, and may be helpful as a gravity marker for prognosis in patients admitted to the ICU. Further research is warranted to gain a better understanding of how these patients respond to common interventions in the ICU and to determine if pharmacologic modulation of HDLVEF improves outcomes.

Paediatric chest wall trauma causing delayed presentation of ventricular arrhythmia.

PubMed

Tegethoff, Angela M; Raney, Emerald; Mendelson, Jenny; Minckler, Michael R

2017-07-24

This report describes a paediatric patient presenting with haemodynamically stable non-sustained ventricular tachycardia 1 day after minor blunt chest trauma. Initial laboratory studies, chest X-ray and echocardiography were normal; however, cardiac MRI revealed precordial haematoma, myocardial contusion and small pericardial effusion. Throughout her hospital course, she remained asymptomatic aside from frequent couplets and triplets of premature ventricular contractions. Ectopy was controlled with oral verapamil. This case highlights how significant cardiac injury may be missed with standard diagnostic algorithms. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

[Evaluation of left ventricular diastolic function using gated SPECT with 99mTc-MIBI].

PubMed

Toba, M; Kumita, S I; Mizumura, S; Cho, K; Kijima, T; Takahama, K; Kumazaki, T

1996-04-01

Development of 3 head SPECT system and 99mTc-labeled radiopharmaceuticals enable us to evaluate left ventricular systolic function on the basis of once gated SPECT routine. This study was focused on assessment of left ventricular diastolic function using 99mTc-MIBI gated SPECT data. Twenty nine patients with ischemic heart diseases underwent 99mTc-MIBI gated SPECT and 99mTc-HSAD ventriculographic assessment of left ventricular diastolic function within 1 month. Region of interests (ROI), simultaneously calculating counts per pixel within ROI, were placed over whole myocardium of 16 serial phasic images reconstructed from gated SPECT data, following selection of the central slice within short axial images. Then, 29 patients were classified into 3 patterns of phase count curve (normal, mixed, and delayed relaxation = diastolic dysfunction). Moreover, 1/3 Count Decreasing Fraction (1/3 CDF) was calculated on the same concept as 1/3 FF. The curve pattern showed significant differences between normal and abnormal group divided on the basis of established indices such as 1/3 FF and PFR, and 1/3 CDF has correlations with 1/3 FF (r = 0.61) and PFR (r = 0.58). We concluded that the new parameters drawn from 99mTc-MIBI gated SPECT data might be feasible for evaluation of diastolic function.

Cardiomyopathy in Boxer dogs: a retrospective study of the clinical presentation, diagnostic findings and survival.

PubMed

Palermo, Valentina; Stafford Johnson, Michael J; Sala, Elisabetta; Brambilla, Paola G; Martin, Mike W S

2011-03-01

To retrospectively compare and contrast the clinical presentation, diagnostic findings and survival in Boxer dogs with cardiomyopathy, with or without left ventricular (LV) systolic failure. Medical records of Boxers referred between 1993 and 2008 in which a diagnosis of ventricular arrhythmias and/or cardiomyopathy was made, were reviewed. Dogs were divided into two groups according to their left ventricular (LV) systolic diameter, group A normal (20 dogs) or group B dilated (59 dogs). Dogs in group A had a better outcome than dogs in group B (median survival time of 124 and 17 weeks respectively, p < 0.001). In group B, dogs with a history of collapse had a worse outcome (median survival time of 10 weeks) compared with dogs not showing collapse (median survival time 24 weeks) (p = 0.031). The majority of dogs, in this UK study, presented with the myocardial dysfunction form of the disease, with LV dilation and congestive heart failure signs. The prognosis was worse in dogs with LV dilation compared to dogs with a normal LV and ventricular arrhythmias. In the Boxers with LV dilation, dogs with collapse had a worse prognosis than those without. Copyright © 2011 Elsevier B.V. All rights reserved.

Tachycardia, reduced vagal capacity, and age-dependent ventricular dysfunction arising from diminished expression of the presynaptic choline transporter.

PubMed

English, Brett A; Appalsamy, Martin; Diedrich, Andre; Ruggiero, Alicia M; Lund, David; Wright, Jane; Keller, Nancy R; Louderback, Katherine M; Robertson, David; Blakely, Randy D

2010-09-01

Healthy cardiovascular function relies on a balanced and responsive integration of noradrenergic and cholinergic innervation of the heart. High-affinity choline uptake by cholinergic terminals is pivotal for efficient ACh production and release. To date, the cardiovascular impact of diminished choline transporter (CHT) expression has not been directly examined, largely due to the transporter's inaccessibility in vivo. Here, we describe findings from cardiovascular experiments using transgenic mice that bear a CHT genetic deficiency. Whereas CHT knockout (CHT(-/-)) mice exhibit early postnatal lethality, CHT heterozygous (CHT(+/-)) mice survive, grow, and reproduce normally and exhibit normal spontaneous behaviors. However, the CHT(+/-) mouse heart displays significantly reduced levels of high-affinity choline uptake accompanied by significantly reduced levels of ACh. Telemeterized recordings of cardiovascular function in these mice revealed tachycardia and hypertension at rest. After treadmill exercise, CHT(+/-) mice exhibited slower heart rate recovery, consistent with a diminished cholinergic reserve, a contention validated through direct vagal nerve stimulation. Echocardiographic and histological experiments revealed an age-dependent decrease in fractional shortening, increased left ventricular dimensions, and increased ventricular fibrosis, consistent with ventricular dysfunction. These cardiovascular phenotypes of CHT(+/-) mice encourage an evaluation of humans bearing reduced CHT expression for their resiliency in maintaining proper heart function as well as risk for cardiovascular disease.

[Influence of pacing site on myocardial transmural dispersion of repolarization in intact normal and dilated cardiomyopathy dogs].

PubMed

Bai, Rong; Pu, Jun; Liu, Nian; Lu, Jia-Gao; Zhou, Qiang; Ruan, Yan-Fei; Niu, Hui-Yan; Wang, Lin

2003-12-25

In order to verify the hypothesis that left ventricular epicardial (LV-Epi) pacing and biventricular (BiV) pacing unavoidably influence the myocardial electrophysiological characters and may result in high risk of malignant ventricular arrhythmia, we calculated, in both normal mongrel dogs and dog models with rapid-right-ventricular-pacing induced dilated cardiomyopathy congestive heart failure (DCM-CHF), the monophasic action potential duration (MAPD) and the transmural dispersion of repolarization (TDR) in intracardiac electrogram together with the QT interval and T(peak)-T(end) (T(p(-T(e)) interval in surface electrocardiogram (ECG) during LV-Epi and BiV pacing, compared with those during right ventricular endocardial (RV-Endo) pacing. To prepare the DCM-CHF dog model, rapid right ventricular pacing (250 bpm) was performed for 23.6+/-2.57 days to the dog. All the normal and DCM-CHF dogs were given radio frequency catheter ablation (RFCA) to His bundle with the guide of X-ray fluoroscopy. After the RFCA procedures, the animals were under the situation of complete atrioventricular block so that the canine heart rates could be voluntarily controlled in the following experiments. After a thoracotomy, ECG and monophasic action potentials (MAP) of subendocardial, subepicardial and mid-layer myocardium were recorded synchronously in 8 normal and 5 DCM-CHF dogs during pacing from endocardium of RV apex (RV-Endo), epicardium of LV anterior wall (LV-Epi) and simultaneously both of the above (biventricular, BiV), the later was similar to the ventricular resynchronization therapy to congestive heart failure patients in clinic. The Tp-Te) meant the interval from the peak to the end of T wave, which was a representative index of TDR in surface ECG. The TDR was defined as the difference between the longest and the shortest MAPD of subendocardial, subepicardial and mid-layer myocardium. Our results showed that in normal dogs, pacing participating of LV (LV-Epi, BiV) prolonged MAPD of all the three layers of the myocardium (P<0.05) with the character that mid-layer MAPD was the longest and subepicardial MAPD was the shortest following subendocardial MAPD. At the same time, TDR prolonged from 26.75 ms at RV-Endo pacing to 37.54 ms at BiV pacing and to 47.16 ms at LV-Epi pacing (P<0.001). Meanwhile in surface ECG, BiV and LV-Epi pacing resulted in a longer Tp-Te) interval compared with RV-Endo pacing (P<0.01), without parallel QT interval prolongation. Furthermore, all the DCM-CHF model dogs showed manifestations of congestive heart failure and enlargement of left ventricles. Based on the lengthening of mid-layer MAPD from 257.35 ms to 276.30 ms (P<0.0001) and increase of TDR from 27.58 ms to 33.80 ms (P equals;0.002) in DCM-CHF model due to the structural disorders of myocardium compared with the normal dog, LV-Epi and BiV pacing also led to the effect of prolonging MAPD of three layers of the myocardium and enlarging TDR. From these results we make the conclusions that prolongation of MAPD of subendocardial, subepicardial and mid-layer myocardium and increase in TDR during pacing participating of LV (LV-Epi, BiV) may contribute to the formation of unidirectional block and reentry, which play roles or at least are the high risk factors in the development of malignant ventricular arrhythmia, especially in case of structural disorders of myocardium. These findings must be considered seriously when ventricular resynchronization therapy is performed to congestive heart failure patients.

Does quantitative left ventricular regional wall motion change after fibrous tissue resection in endomyocardial fibrosis?

PubMed

Salemi, Vera Maria Cury; Fernandes, Fabio; Sirvente, Raquel; Nastari, Luciano; Rosa, Leonardo Vieira; Ferreira, Cristiano A; Pena, José Luiz Barros; Picard, Michael H; Mady, Charles

2009-01-01

We compared left ventricular regional wall motion, the global left ventricular ejection fraction, and the New York Heart Association functional class pre- and postoperatively. Endomyocardial fibrosis is characterized by fibrous tissue deposition in the endomyocardium of the apex and/or inflow tract of one or both ventricles. Although left ventricular global systolic function is preserved, patients exhibit wall motion abnormalities in the apical and inferoapical regions. Fibrous tissue resection in New York Heart Association FC III and IV endomyocardial fibrosis patients has been shown to decrease morbidity and mortality. We prospectively studied 30 patients (20 female, 30+/-10 years) before and 5+/-8 months after surgery. The left ventricular ejection fraction was determined using the area-length method. Regional left ventricular motion was measured by the centerline method. Five left ventricular segments were analyzed pre- and postoperatively. Abnormality was expressed in units of standard deviation from the mean motion in a normal reference population. Left ventricular wall motion in the five regions did not differ between pre- and postoperative measurements. Additionally, the left ventricular ejection fraction did not change after surgery (0.45+/-0.13% x 0.43+/-0.12% pre- and postoperatively, respectively). The New York Heart Association functional class improved to class I in 40% and class II in 43% of patients postoperatively (p<0.05). Although endomyocardial fibrosis patients have improved clinical symptoms after surgery, the global left ventricular ejection fraction and regional wall motion in these patients do not change. This finding suggests that other explanations, such as improvements in diastolic function, may be operational.

Bayesian Classification Models for Premature Ventricular Contraction Detection on ECG Traces.

PubMed

Casas, Manuel M; Avitia, Roberto L; Gonzalez-Navarro, Felix F; Cardenas-Haro, Jose A; Reyna, Marco A

2018-01-01

According to the American Heart Association, in its latest commission about Ventricular Arrhythmias and Sudden Death 2006, the epidemiology of the ventricular arrhythmias ranges from a series of risk descriptors and clinical markers that go from ventricular premature complexes and nonsustained ventricular tachycardia to sudden cardiac death due to ventricular tachycardia in patients with or without clinical history. The premature ventricular complexes (PVCs) are known to be associated with malignant ventricular arrhythmias and sudden cardiac death (SCD) cases. Detecting this kind of arrhythmia has been crucial in clinical applications. The electrocardiogram (ECG) is a clinical test used to measure the heart electrical activity for inferences and diagnosis. Analyzing large ECG traces from several thousands of beats has brought the necessity to develop mathematical models that can automatically make assumptions about the heart condition. In this work, 80 different features from 108,653 ECG classified beats of the gold-standard MIT-BIH database were extracted in order to classify the Normal, PVC, and other kind of ECG beats. Three well-known Bayesian classification algorithms were trained and tested using these extracted features. Experimental results show that the F1 scores for each class were above 0.95, giving almost the perfect value for the PVC class. This gave us a promising path in the development of automated mechanisms for the detection of PVC complexes.

An electrocardiographic scoring system for distinguishing right ventricular outflow tract arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy from idiopathic ventricular tachycardia.

PubMed

Hoffmayer, Kurt S; Bhave, Prashant D; Marcus, Gregory M; James, Cynthia A; Tichnell, Crystal; Chopra, Nagesh; Moxey, Laura; Krahn, Andrew D; Dixit, Sanjay; Stevenson, William; Calkins, Hugh; Badhwar, Nitish; Gerstenfeld, Edward P; Scheinman, Melvin M

2013-04-01

Ventricular arrhythmias in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) and idiopathic ventricular tachycardia (VT) can share a left bundle branch block/inferior axis morphology. We previously reported electrocardiogram characteristics during outflow tract ventricular arrhythmias that helped distinguish VT related to ARVD/C from idiopathic VT. To prospectively validate these criteria. We created a risk score by using a derivation cohort. Two experienced electrophysiologists blinded to the diagnosis prospectively scored patients with VT/premature ventricular contractions (PVCs) with left bundle branch block/inferior axis pattern in a validation cohort of 37 ARVD/C tracings and 49 idiopathic VT tracings. All patients with ARVD/C had their diagnosis confirmed based on the revised task force criteria. Patients with idiopathic VT were selected based on structurally normal hearts with documented right ventricular outflow tract VT successfully treated with ablation. The scoring system provides 3 points for sinus rhythm anterior T-wave inversions in leads V1-V3 and during ventricular arrhythmia: 2 points for QRS duration in lead I≥120 ms, 2 points for QRS notching, and 1 point for precordial transition at lead V5 or later. A score of 5 or greater was able to correctly distinguish ARVD/C from idiopathic VT 93% of the time, with a sensitivity of 84%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 91%. We describe a simple scoring algorithm that uses 12-lead electrocardiogram characteristics to effectively distinguish right ventricular outflow tract arrhythmias originating from patients with ARVD/C versus patients with idiopathic VT. Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Using impedance cardiography to assess left ventricular systolic function via postural change in patients with heart failure.

PubMed

DeMarzo, Arthur P; Calvin, James E; Kelly, Russell F; Stamos, Thomas D

2005-01-01

For the diagnosis and management of heart failure, it would be useful to have a simple point-of-care test for assessing ventricular function that could be performed by a nurse. An impedance cardiography (ICG) parameter called systolic amplitude (SA) can serve as an indicator of left ventricular systolic function (LVSF). This study tested the hypothesis that patients with normal LVSF should have a significant increase in SA in response to an increase in end-diastolic volume caused by postural change from sitting upright to supine, while patients with depressed LVSF associated with heart failure should have a minimal increase or a decrease in SA from upright to supine. ICG data were obtained in 12 patients without heart disease and with normal LVSF and 18 patients with clinically diagnosed heart failure. Consistent with the hypothesis, patients with normal LVSF had a significant increase in SA from upright to supine, whereas heart failure patients had a minimal increase or a decrease in SA from upright to supine. This ICG procedure may be useful for monitoring the trend of patient response to titration of beta blockers and other medications. ICG potentially could be used to detect worsening LVSF and provide a means of measurement for adjusting treatment.

Mechanisms of decreased left ventricular preload during continuous positive pressure ventilation in ARDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dhainaut, J.F.; Devaux, J.Y.; Monsallier, J.F.

1986-07-01

Continuous positive pressure ventilation is associated with a reduction in left ventricular preload and cardiac output, but the mechanisms responsible are controversial. The decrease in left ventricular preload may result exclusively from a decreased systemic venous return due to increased pleural pressure, or from an additional effect such as decreased left ventricular compliance. To determine the mechanisms responsible, we studied the changes in cardiac output induced by continuous positive pressure ventilation in eight patients with the adult respiratory distress syndrome. We measured cardiac output by thermodilution, and biventricular ejection fraction by equilibrium gated blood pool scintigraphy. Biventricular end-diastolic volumes weremore » then calculated by dividing stroke volume by ejection fraction. As positive end-expiratory pressure increased from 0 to 20 cm H/sub 2/O, stroke volume and biventricular end-diastolic volumes fell about 25 percent, and biventricular ejection fraction remained unchanged. At 20 cm H/sub 2/O positive end-expiratory pressure, volume expansion for normalizing cardiac output restored biventricular end-diastolic volumes without markedly changing biventricular end-diastolic transmural pressures. The primary cause of the reduction in left ventricular preload with continuous positive pressure ventilation appears to be a fall in venous return and hence in right ventricular stroke volume, without evidence of change in left ventricular diastolic compliance.« less

Flecainide-induced proarrhythmia is attributed to abnormal changes in repolarization and refractoriness in perfused guinea-pig heart.

PubMed

Osadchii, Oleg E

2012-11-01

Flecainide is nonselective Na(+) channel blocker which may also inhibit I(Kr), the rapid component of the delayed rectifier. This study was designed to explore if proarrhythmic responses to flecainide noted in cardiac patients may be partly attributed to abnormal changes in repolarization and refractoriness. Monophasic action potential duration (APD) and effective refractory periods (ERP) were assessed at distinct epicardial and endocardial sites along with volume-conducted ECG recordings in isolated perfused guinea-pig heart preparations. Flecainide was found to prolong ventricular repolarization, with effect being greater at the left ventricular compared with the right ventricular epicardium. This change translated to reversal of the normal right ventricular-to-left ventricular transepicardial APD difference determined before drug infusion. An inverse correlation between local epicardial APD and corresponding activation time values seen at baseline was eliminated in flecainide-treated hearts, indicating the activation-to-repolarization uncoupling. Over transmural plane, flecainide produced a greater ERP lengthening at endocardium than epicardium, thus markedly increasing ERP dispersion across ventricular wall. Spontaneous short-lasting episodes of monomorphic ventricular tachycardia were observed in 45% of heart preparations upon flecainide infusion. In conclusion, in nonischemic guinea-pig heart, flecainide-induced proarrhythmia may be partly attributed to abnormal spatial gradients in repolarization and refractoriness and impaired transepicardial activation-to-repolarization coupling.

Isometric exercise: cardiovascular responses in normal and cardiac populations.

PubMed

Hanson, P; Nagle, F

1987-05-01

Isometric exercise produces a characteristic pressor increase in blood pressure which may be important in maintaining perfusion of muscle during sustained contraction. This response is mediated by combined central and peripheral afferent input to medullary cardiovascular centers. In normal individuals the increase in blood pressure is mediated by a rise in cardiac output with little or no change in systemic vascular resistance. However, the pressor response is also maintained during pharmacologic blockade or surgical denervation by increasing systemic vascular resistance. Left ventricular function is normally maintained or improves in normal subjects and cardiac patients with mild impairment of left ventricular contractility. Patients with poor left ventricular function may show deterioration during isometric exercise, although this pattern of response is difficult to predict from resting studies. Recent studies have shown that patients with uncomplicated myocardial infarction can perform submaximum isometric exercise such as carrying weights in the range of 30 to 50 lb without difficulty or adverse responses. In addition, many patients who show ischemic ST depression or angina during dynamic exercise may have a reduced ischemic response during isometric or combined isometric and dynamic exercise. Isometric exercises are frequently encountered in activities of daily living and many occupational tasks. Cardiac patients should be gradually exposed to submaximum isometric training in supervised cardiac rehabilitation programs. Specific job tasks that require isometric or combined isometric and dynamic activities may be evaluated by work simulation studies. This approach to cardiac rehabilitation may facilitate patients who wish to return to a job requiring frequent isometric muscle contraction. Finally, there is a need for additional research on the long-term effects of isometric exercise training on left ventricular hypertrophy and performance. The vigorous training regimens currently utilized by international class and professional athletes should stimulate longitudinal studies of physiologic and pathophysiologic outcomes of intense isometric exercise training programs.

Reversal of pulmonary hypertension after percutaneous closure of congenital renal arteriovenous fistula in a 74-year old woman.

PubMed

Brar, Vijaywant; Bernardo, Nelson; Suddath, William; Weissman, Gaby; Asch, Federico; Campia, Umberto

2015-01-01

We report the case of a large right renal arteriovenous fistula (AVF) in a 74-year old woman who presented with heart failure. Transthoracic echocardiography revealed normal left ventricular size and systolic function (ejection fraction 60-65%), moderately dilated right ventricle with severely depressed systolic function, and severe pulmonary hypertension. Right heart catheterization confirmed the elevated pulmonary pressures and showed a high cardiac output. Physical examination was remarkable for a right flank bruit. An abdominal ultrasound revealed an AVF originating from the distal right renal artery and dilated suprarenal inferior vena cava and hepatic veins. These findings were confirmed with an abdominal MRI. Percutaneous endovascular closure of the right renal AVF was successfully performed, with immediate reduction of pulmonary pressures and normalization of cardiac output. The patient's symptoms improved, and a post intervention echocardiogram revealed normalization of right ventricular size. Copyright © 2015 Elsevier Inc. All rights reserved.

Computerized mapping of fibrillation in normal ventricular myocardium

NASA Astrophysics Data System (ADS)

Chen, Peng-Sheng; Garfinkel, Alan; Weiss, James N.; Karagueuzian, Hrayr S.

1998-03-01

It is well known that the ability to fibrillate is intrinsic to a normal ventricle that exceeds a critical mass. The questions we address are how is ventricular fibrillation (VF) initiated and perpetuated in normal myocardium, and why is VF not seen more often in the general population if all ventricles have the ability to fibrillate. To study the mechanisms of VF, we used computerized mapping techniques with up to 512 channels of simultaneous multisite recordings for data acquisition. The data were then processed for dynamic display of the activation patterns and for mathematical analyses of the activation intervals. The results show that in normal ventricles, VF can be initiated by a single strong premature stimulus given during the vulnerable period of the cardiac cycle. The initial activations form a figure-eight pattern. Afterward, VF will perpetuate itself without any outside help. The self-perpetuation itself is due to at least two factors. One is that single wave fronts spontaneously break up into two or more wavelets. The second is that when two wavelets intersect perpendicular to each other, the second wavelet is broken by the residual refractoriness left over from the first wavelet. Mathematical analyses of the patterns of activation during VF revealed that VF is a form of chaos, and that transition from ventricular tachycardia (VT) to VF occurs via the quasiperiodic route. In separate experiments, we found that we can convert VF to VT by tissue size reduction. The physiological mechanism associated with the latter transition appears to be the reduction of the number of reentrant wave fronts and wandering wavelets. Based on these findings, we propose that the reentrant wave fronts and the wandering wavelets serve as the physiological equivalent of coupled oscillators. A minimal number of oscillators is needed for VF to perpetuate itself, and to generate chaotic dynamics; hence a critical mass is required to perpetuate VF. We conclude that VF in normal myocardium is a form of reentrant cardiac arrhythmia. A strong electrical stimulus initiates single or dual reentrant wave fronts that break up into multiple wavelets. Sometimes short-lived reentry is also generated during the course of VF. These organized reentrant and broken wavelets serve as coupled oscillators that perpetuate VF and maintain chaos. Although the ability to support these oscillators exists in a normal ventricle, the triggers required to generate them are nonexistent in the normal heart. Therefore, VF and sudden death do not happen to most people with normal ventricular myocardium.

Pharmacological heart rate lowering in patients with a preserved ejection fraction-review of a failing concept.

PubMed

Meyer, Markus; Rambod, Mehdi; LeWinter, Martin

2018-07-01

Epidemiological studies have demonstrated that high resting heart rates are associated with increased mortality. Clinical studies in patients with heart failure and reduced ejection fraction have shown that heart rate lowering with beta-blockers and ivabradine improves survival. It is therefore often assumed that heart rate lowering is beneficial in other patients as well. Here, we critically appraise the effects of pharmacological heart rate lowering in patients with both normal and reduced ejection fraction with an emphasis on the effects of pharmacological heart rate lowering in hypertension and heart failure. Emerging evidence from recent clinical trials and meta-analyses suggest that pharmacological heart rate lowering is not beneficial in patients with a normal or preserved ejection fraction. This has just begun to be reflected in some but not all guideline recommendations. The detrimental effects of pharmacological heart rate lowering are due to an increase in central blood pressures, higher left ventricular systolic and diastolic pressures, and increased ventricular wall stress. Therefore, we propose that heart rate lowering per se reproduces the hemodynamic effects of diastolic dysfunction and imposes an increased arterial load on the left ventricle, which combine to increase the risk of heart failure and atrial fibrillation. Pharmacologic heart rate lowering is clearly beneficial in patients with a dilated cardiomyopathy but not in patients with normal chamber dimensions and normal systolic function. These conflicting effects can be explained based on a model that considers the hemodynamic and ventricular structural effects of heart rate changes.

Does oxidative stress modulate left ventricular diastolic function in asymptomatic subjects with hereditary hemochromatosis?

PubMed

Shizukuda, Yukitaka; Bolan, Charles D; Tripodi, Dorothy J; Sachdev, Vandana; Nguyen, Tammy T; Botello, Gilberto; Yau, Yu-Ying; Sidenko, Stanislav; Inez, Ernst; Ali, Mir I; Waclawiw, Myron A; Leitman, Susan F; Rosing, Douglas R

2009-11-01

Little is known about the early mechanisms mediating left ventricular (LV) diastolic dysfunction in patients with hereditary hemochromatosis (HH). However, the increased oxidative stress related to iron overload may be involved in this process, and strain rate (SR), a sensitive echocardiography-derived measure of diastolic function, may detect such changes. we evaluated the relationship between left ventricular diastolic function measured with tissue Doppler SR and oxidative stress in asymptomatic HH subjects and control normal subjects. Ninety-four consecutive visits of 43 HH subjects, age 30-74 (50 +/- 10, mean +/- SD), and 37 consecutive visits of 21 normal volunteers, age 30-63 (48 +/- 8), were evaluated over a 3-year period. SR was obtained from the basal septum in apical four-chamber views. All patients had confirmed C282Y homozygosity, a documented history of iron overload, and were New York Heart Association functional class I. Normal volunteers lacked HFE gene mutations causing HH. In the HH subjects, the SR demonstrated moderate but significant correlations with biomarkers of oxidative stress; however, no correlations were noted in normal subjects. The biomarkers of iron overload per se did not show significant correlations with the SR. Although our study was limited by the relatively small subject number, these results suggest that a possible role of oxidative stress to affect LV diastolic function in asymptomatic HH subjects and SR imaging may be a sensitive measure to detect that effect.

Bacopa monnieri extract increases rat coronary flow and protects against myocardial ischemia/reperfusion injury.

PubMed

Srimachai, Sirintorn; Devaux, Sylvie; Demougeot, Celine; Kumphune, Sarawut; Ullrich, Nina D; Niggli, Ernst; Ingkaninan, Kornkanok; Kamkaew, Natakorn; Scholfield, C Norman; Tapechum, Sompol; Chootip, Krongkarn

2017-02-20

This study explored Bacopa monnieri, a medicinal Ayurvedic herb, as a cardioprotectant against ischemia/reperfusion injury using cardiac function and coronary flow as end-points. In normal isolated rat hearts, coronary flow, left ventricular developed pressure, heart rate, and functional recovery were measured using the Langendorff preparation. Hearts were perfused with either (i) Krebs-Henseleit (normal) solution, (control), or with 30, 100 μg/ml B. monnieri ethanolic extract (30 min), or (ii) with normal solution or extract for 10 min preceding no-perfusion ischemia (30 min) followed by reperfusion (30 min) with normal solution. Infarct volumes were measured by triphenyltetrazolium staining. L-type Ca 2+ -currents (I Ca, L ) were measured by whole-cell patching in HL-1 cells, a mouse atrial cardiomyocyte cell line. Cytotoxicity of B. monnieri was assessed in rat isolated ventricular myocytes by trypan blue exclusion. In normally perfused hearts, B. monnieri increased coronary flow by 63 ± 13% (30 μg/ml) and 216 ± 21% (100 μg/ml), compared to control (5 ± 3%) (n = 8-10, p < 0.001). B. monnieri treatment preceding ischemia/reperfusion improved left ventricular developed pressure by 84 ± 10% (30 μg/ml), 82 ± 10% (100 μg/ml) and 52 ± 6% (control) compared to pre- ischemia/reperfusion. Similarly, functional recovery showed a sustained increase. Moreover, B. monnieri (100 μg/ml) reduced the percentage of infarct size from 51 ± 2% (control) to 25 ± 2% (n = 6-8, p < 0.0001). B. monnieri (100 μg/ml) reduced I Ca, L by 63 ± 4% in HL-1 cells. Ventricular myocyte survival decreased at higher concentrations (50-1000 μg/ml) B. monnieri. B. monnieri improves myocardial function following ischemia/reperfusion injury through recovery of coronary blood flow, contractile force and decrease in infarct size. Thus this may lead to a novel cardioprotectant strategy.

Subclassification of left ventricular hypertrophy based on dilation stratifies coronary artery disease patients with distinct risk.

PubMed

Huang, Bao-Tao; Peng, Yong; Liu, Wei; Zhang, Chen; Huang, Fang-Yang; Wang, Peng-Ju; Zuo, Zhi-Liang; Liao, Yan-Biao; Chai, Hua; Li, Qiao; Zhao, Zhen-Gang; Luo, Xiao-Lin; Ren, Xin; Huang, Kai-Sen; Meng, Qing-Tao; Chen, Chi; Huang, De-Jia; Chen, Mao

2014-10-01

A new 4-tired classification of left ventricular hypertrophy (LVH) based on LV concentricity and dilation has been proposed; however, the association between the new categorization of LV geometry and outcomes in patients with coronary artery disease (CAD) is still unknown. All the 2297 patients with CAD included underwent echocardiographic examination prior to discharge. Left ventricular mass (LVM) was calculated, and left ventricular end-diastolic volume (EDV) was indexed by body surface area (BSA). Study cohort was divided into five groups according to LV geometry: (i) eccentric nondilated LVH (normal LVM/EDV((2/3)) and EDV/BSA) (n = 129); (ii) eccentric dilated LVH (normal LVM/EDV((2/3)) with increased EDV/BSA) (n = 222); (iii) concentric nondilated LVH (increased LVM/EDV((2/3)) with normal EDV/BSA) (n = 441); (iv) concentric dilated LVH (increased LVM/EDV((2/3)) and EDV/BSA) (n = 118); and (v) normal LV mass (n = 1387). Dilated LVH was associated with a higher event rates of all-cause death (eccentric 13·1% vs. 3·1%; concentric 13·6% vs. 8·4%) and composite events (eccentric: 17·6% vs. 5·4%; concentric: 18·6% vs. 12·7%) compared with nondilated LVH. While eccentric nondilated LVH had comparable risk for adverse outcomes compared with normal LV mass (all-cause death: relative risk (RR) 0·68, 95% confidential interval (CI) 0·25-1·85; composite events: RR 0·75, 95% CI 0·36-1·58). Cox regression analyses showed that eccentric dilated LVH had the highest propensity to all-cause death (adjusted hazard ratio [aHR] 2·752 [95% CI 1·749-4·328], P < 0·001) and composite events (aHR 2·462 [95% CI 1·688-3·592], P < 0·001). In patients with CAD, dilated LVH and nondilated LVH provide distinct prognostic information. Eccentric nondilated LVH does not predict adverse outcomes. © 2014 Stichting European Society for Clinical Investigation Journal Foundation.

Factors influencing recovery of left ventricular structure in patients with chronic heart failure.

PubMed

Duan, Hong-Yan; Wu, Xue-Si; Han, Zhi-Hong; Guo, Yong-Fang; Fang, Shan-Juan; Zhang, Xiao-Xia; Wang, Chun-Mei

2011-09-01

Angiotensin converting enzyme (ACE) inhibitors and β-blockers (βB) have beneficial effects on left ventricular (LV) remodeling, alleviate symptoms and reduce morbidity and mortality in patients with chronic heart failure (CHF). However the correlation between the d osages of ACE inhibitors, βB, and recovery of LV structure remains controversial. Clinical factors associated with recovery of normal ventricular structure in CHF patients receiving medical therapy are poorly defined. Here we aimed to identify variables associated with recovery of normal or near-normal structure in patients with CHF. We recruited 231 consecutive CHF outpatients, left ventricular ejection fraction (LVEF) ≤ 40% and left ventricular end diastolic diameter (LVEDD) > 55/50 mm (male/female), who were receiving optimal pharmacotherapy between January 2001 and June 2009, and followed them until December 31, 2009. They were divided into three groups according to LVEDD and whether they were still alive at final follow-up: group A, LVEDD ≤ 60/55 mm (male/female); group B, LVEDD > 60/55 mm (male/female); and group C, those who died before final follow-up. Apart from group C, univariate analysis was performed followed by Logistic multivariate analysis to determine the predictors of recovery of LV structure. A total of 217 patients completed follow-up, and median follow-up time was 35 months (range 6 - 108). Twenty-five patients died during that period; the all-cause mortality rate was 11.5%. Group A showed clinical characteristics as follows: the shortest duration of disease and shortest QRS width, the lowest N-terminal brain natriuretic peptide (NT-proBNP) at baseline, the highest dose of βB usage, the highest systolic blood pressure (SBP), diastolic blood pressure (DBP) and the lowest New York Heart Association (NYHA) classification, serum creatinine, uric acid, total bilirubin and NT-proBNP after treatment. Logistic multivariate analysis was performed according to recovery or no recovery of LV structure. Data showed that LVEF at follow-up (P = 0.013), mitral regurgitation at baseline (P = 0.020), LVEDD at baseline (P = 0.031), and βB dosage (P = 0.041) were independently associated with recovery of LV diameter. Our study suggests that four clinical variables may predict recovery of LV structure to normal or near-normal values with optimal drug therapy alone, and may be used to discriminate between patients who should receive optimal pharmacotherapy and those who require more aggressive therapeutic interventions.

Visualisation of exercise-induced ischaemia of the right ventricle by thallium-201 single photon emission computed tomography.

PubMed Central

Chiba, J.; Takeishi, Y.; Abe, S.; Tomoike, H.

1997-01-01

OBJECTIVE: Exercise thallium-201 (201T1) single photon emission computed tomography (SPECT) has been used to detect potential ischaemia in the left ventricular myocardium but not in the right ventricle. The purpose of this study was to establish the clinical usefulness of a right ventricular polar map of 201T1 SPECT for visualisation of exercise-induced right ventricular ischaemia. METHODS: Myocardial 201T1 SPECT was obtained immediately after treadmill exercise in 97 patients with suspected coronary artery disease. A region of interest was placed over the right ventricle (RV) on post-stress transaxial images. Short axis images of this region were generated and reconstructed as a bull's eye polar map. Normal ranges of RV 201T1 uptake were determined in 12 patients with normal coronary arteries. Scintigraphic criteria for identifying RV perfusion abnormality were derived from 25 patients with right coronary artery (RCA) stenosis greater than 75%. These criteria were applied to 60 consecutive patients with suspected coronary artery disease. RESULTS: Perfusion defects in the RV were larger in patients with proximal RCA stenosis than in those with distal RCA stenosis (mean (SD) 28 (16)% v 6 (5)%, P < 0.001). The sensitivity and specificity of the RV polar map for the detection of proximal RCA stenosis were 67% (8/12) and 98% (47/48), respectively. RV perfusion defects became undetectable in 9 patients who had successful percutaneous transluminal coronary angioplasty to a proximal RCA lesion. CONCLUSIONS: A right ventricular polar map display was useful for visualising exercise-induced right ventricular ischaemia. Images PMID:9038692

Randomised trial of low-dose amiodarone in severe congestive heart failure. Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (GESICA)

PubMed

Doval, H C; Nul, D R; Grancelli, H O; Perrone, S V; Bortman, G R; Curiel, R

1994-08-20

In severe heart failure many deaths are sudden and are presumed to be due to ventricular arrhythmias. The GESICA trial evaluated the effect of low-dose amiodarone on two-year mortality in patients with severe heart failure. Our prospective multicentre trial included 516 patients on optimal standard treatment for heart failure. Patients were randomised to 300 mg/day amiodarone (260) or to standard treatment (256). Intention-to-treat analysis showed 87 deaths in the amiodarone group (33.5%) compared with 106 in the control group (41.4%) (risk reduction 28%; 95% CI 4%-45%; log rank test p = 0.024). There were reductions in both sudden death (risk reduction 27%; p = 0.16) and death due to progressive heart failure (risk reduction 23%; p = 0.16). Fewer patients in the amiodarone group died or were admitted to hospital due to worsening heart failure (119 versus 149 in the control group; risk reduction 31%; 95% CI 13-46%; p = 0.0024). The decrease in mortality and hospital admission was present in all subgroups examined and independent of the presence of non-sustained ventricular tachycardia. Side-effects were reported in 17 patients (6.1%); amiodarone was withdrawn in 12. Low-dose amiodarone proved to be an effective and reliable treatment, reducing mortality and hospital admission in patients with severe heart failure independently of the presence of complex ventricular arrhythmias.

Hyperthyroidism as a reversible cause of right ventricular overload and congestive heart failure

PubMed Central

Di Giovambattista, Raniero

2008-01-01

We describe a case of severe congestive heart failure and right ventricular overload associated with overt hyperthyroidism, completely reversed with antithyroid therapy in a few week. It represents a very unusual presentation of overt hyperthyroidism because of the severity of right heart failure. The impressive right ventricular volume overload made mandatory to perform transesophageal echo and angio-TC examination to exclude the coexistence of ASD or anomalous pulmonary venous return. Only a few cases of reversible right heart failure, with or without pulmonary hypertension, have been reported worldwide. In our case the most striking feature has been the normalization of the cardiovascular findings after six weeks of tiamazole therapy. PMID:18549503

Polymorphic ventricular tachycardia due to variant angina diagnosed on Holter monitoring and confirmed with cold pressor test.

PubMed

Öztürk, Semi; Aktemur, Tuğba; Kalyoncuoğlu, Muhsin; Durmuş, Gündüz; Can, Mehmet

2017-04-01

A 52-year-old man complaining of persistent recurring chest pain at night underwent coronary angiogram at another institution. Normal coronaries were observed and he was discharged with muscle spasmolytic prescription. Since symptoms had continued, 24-hour Holter monitoring was ordered at our facility and results revealed huge ST elevation and polymorphic ventricular tachycardia. Cold pressor test performed in catheterization laboratory also resulted in ventricular tachycardia. Nifedipine was prescribed and follow-up Holter monitoring revealed no further vasospastic episodes. Utility of 24-hour Holter rhythm monitoring and cold pressor test in patients with recurrent chest pain at night is demonstrated in this report.

Cytoskeletal role in the transition from compensated to decompensated hypertrophy during adult canine left ventricular pressure overloading

NASA Technical Reports Server (NTRS)

Tagawa, H.; Koide, M.; Sato, H.; Zile, M. R.; Carabello, B. A.; Cooper, G. 4th

1998-01-01

Increased microtubule density causes cardiocyte contractile dysfunction in right ventricular (RV) pressure-overload hypertrophy, and these linked phenotypic and contractile abnormalities persist and progress during the transition to failure. Although more severe in cells from failing than hypertrophied RVs, the mechanical defects are normalized in each case by microtubule depolymerization. To define the role of increased microtubule density in left ventricular (LV) pressure-overload hypertrophy and failure, in a given LV we examined ventricular mechanics, sarcomere mechanics, and free tubulin and microtubule levels in control dogs and in dogs with aortic stenosis both with LV hypertrophy alone and with initially compensated hypertrophy that had progressed to LV muscle failure. In comparing initial values with those at study 8 weeks later, dogs with hypertrophy alone had a very substantial increase in LV mass but preservation of a normal ejection fraction and mean systolic wall stress. Dogs with hypertrophy and associated failure had a substantial but lesser increase in LV mass and a reduction in ejection fraction, as well as a marked increase in mean systolic wall stress. Cardiocyte contractile function was equivalent, and unaffected by microtubule depolymerization, in cells from control LVs and those with compensated hypertrophy. In contrast, cardiocyte contractile function in cells from failing LVs was quite depressed but was normalized by microtubule depolymerization. Microtubules were increased only in failing LVs. These contractile and cytoskeletal changes, when assayed longitudinally in a given dog by biopsy, appeared in failing ventricles only when wall stress began to increase and function began to decrease. Thus, the microtubule-based cardiocyte contractile dysfunction characteristic of pressure-hypertrophied myocardium, originally described in the RV, obtains equally in the LV but is shown here to have a specific association with increased wall stress.

Limited Ventricular Preload is the Main Reason for Reduced Stress Reserve After Atrial Baffle Repair.

PubMed

Eicken, Andreas; Michel, Julia; Hager, Alfred; Tanase, Daniel; Kaemmerer, Harald; Cleuziou, Julie; Hess, John; Ewert, Peter

2017-02-01

The atrial baffle repair (ABR) significantly improved the fate of patients with transposition of the great arteries (TGA). However, these patients show impaired exercise tolerance and some present severe decline of systemic ventricular function. Intrinsic myocardial weakness, low heart rate response to exercise and diastolic filling impairment are discussed to be causative. Forty-nine long-term survivors with TGA (median age 23.7 year) after ABR were catheterized with measured oxygen consumption in four conditions (baseline, volume, atrial pacing, dobutamine) and the results were compared to 10 normal controls. Median cardiac output was significantly lower in the ABR group (2.2 vs. 2.6 l/min/m 2 ; p = 0.015), and systemic resistance was significantly elevated (28.9 vs. 22.2 U m 2 ; p = 0.04) in comparison with normals. While stroke volume rose by 27% in the control group, it dropped by 7% in patients after ABR at atrial pacing (80/min). Stroke volume increase after dobutamine was significantly lower after ABR in comparison with normal controls (34 vs. 106%; p = 0.001). Higher NYHA class (p = 0.043), degree of tricuspid regurgitation (p = 0.009) and ventricular function (p = 0.028) were associated with lower stroke volume increase. Limited exercise capability of patients after ABR for TGA is primarily due to limited diastolic filling of the ventricles due to stiff non-compliant atrial pathways. Elevated systemic resistance may lead to severe myocardial hypertrophy with possible ischemia and contribute to the multifactorial decline of ventricular function in some patients.

Pressure-volume Relationship in the Stress-echocardiography Laboratory: Does (Left Ventricular End-diastolic) Size Matter?

PubMed

Bombardini, Tonino; Mulieri, Louis A; Salvadori, Stefano; Costantino, Marco Fabio; Scali, Maria Chiara; Marzilli, Mario; Picano, Eugenio

2017-02-01

The variation between rest and peak stress end-systolic pressure-volume relation is an afterload-independent index of left ventricular contractility. Whether and to what extent it depends on end-diastolic volume remains unclear. The aim of this study was to assess the dependence of the delta rest-stress end-systolic pressure-volume relation on end-diastolic volume in patients with negative stress echo and all ranges of resting left ventricular function. We analyzed interpretable data obtained in 891 patients (593 men, age 63 ± 12 years) with ejection fraction 47% ± 12%: 338 were normal or near-normal or hypertensive; 229 patients had coronary artery disease; and 324 patients had ischemic or nonischemic dilated cardiomyopathy. They were studied with exercise (n = 172), dipyridamole (n = 482) or dobutamine (n = 237) stress echocardiography. The end-systolic pressure-volume relation was evaluated at rest and peak stress from raw measurement of systolic arterial pressure by cuff sphygmomanometer and end-systolic volume by biplane Simpson rule 2-dimensional echocardiography. Absolute values of delta rest-stress end-systolic pressure-volume relation were higher for exercise and dobutamine than for dipyridamole. In the overall population, an inverse relationship between end-systolic pressure-volume relation and end-diastolic volume was present at rest (r 2 = 0.69, P < .001) and peak stress (r 2 = 0.56, P < .001), but was absent if the delta rest-stress end-systolic pressure-volume relation was considered (r 2 = 0.13). Left ventricular end-diastolic volume does not affect the rest-stress changes in end-systolic pressure-volume relation in either normal or abnormal left ventricles during physical or pharmacological stress. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Role of gender in heart failure with normal left ventricular ejection fraction.

PubMed

Regitz-Zagrosek, Vera; Brokat, Sebastian; Tschope, Carsten

2007-01-01

Heart failure with normal ejection fraction (HF-NEF) is frequently believed to be more common in women than in men. However, the interaction of gender and age has rarely been analyzed in detail, and knowledge of the distinction between pre- and postmenopausal women is lacking. Some of the studies that have described a higher prevalence of HF-NEF in women relied on clinical diagnoses of HF together with normal systolic function and did not measure diastolic function. This applies to the analysis of patients hospitalized for HF and some epidemiological investigations that agree on the greater prevalence of HF-NEF in women. Population-based studies with echocardiographic determination of diastolic function have suggested equal or greater prevalence of diastolic dysfunction in men. Major risk factors for HF-NEF include hypertension, aging, obesity, diabetes, and ischemia. Hypertension is more frequent in women and can contribute to left ventricular and arterial stiffening in a gender-specific way. Aging, obesity, and diabetes affect myocardial and vascular stiffness differently and lead to different forms of myocardial hypertrophy in women and men. In contrast, ischemia may play a greater role in men. Gender differences in ventricular diastolic distensibility, in vascular stiffness and ventricular/vascular coupling, in skeletal muscle adaptation to HF, and in the perception of symptoms may contribute to a greater rate of HF-NEF in women. The underlying molecular mechanisms include gender differences in calcium handling, in the NO system, and in natriuretic peptides. Estrogen affects collagen synthesis and degradation and inhibits the renin-angiotensin system. Effects of estrogen may provide benefit to premenopausal women, and the loss of its protective mechanisms may render the heart of postmenopausal women more vulnerable. Thus, a number of molecular mechanisms can contribute to the gender differences in HF-NEF.

Left ventricular function during lower body negative pressure

NASA Technical Reports Server (NTRS)

Ahmad, M.; Blomqvist, C. G.; Mullins, C. B.; Willerson, J. T.

1977-01-01

The response of the human left ventricle to lower body negative pressure (LBNP) and the relation between left ventricular function and hemodynamic response were investigated. Ventricular function curves relating stroke volume to end-diastolic volume were obtained in 12 normal men. Volume data were derived from echocardiographic measurements of left ventricular end-systolic and end-diastolic diameters at rest and during lower body negative pressure (LBNP) at minus 40 mm Hg. End-diastolic volume decreased by 19% and stroke volume by 22%. There were no significant changes in heart rate, arterial blood pressure, or end-systolic volume. Thus, moderate levels of LBNP significantly reduce preload and stroke volume without affecting contractile state. The absence of significant changes in heart rate and arterial blood pressure in the presence of a significant reduction in stroke volume is consistent with an increase in systemic peripheral resistance mediated by low-pressure baroreceptors.

A study of hepatic lesions in broiler chickens at processing plants in Saskatchewan

PubMed Central

Hutchison, Thomas W.S.; Riddell, Craig

1990-01-01

A detailed descriptive study was done on broiler chickens with abnormal livers found at processing. Two syndromes were evident: those birds with enlarged, pale, firm livers, designated hepatosis, with Clostridium perfringens type A often isolated; and ascitic birds with cobblestone-appearing livers. Livers with hepatosis had marked proliferation of bile ducts; ascitic livers had normal architecture. Hearts from birds with ascites had elevated right ventricular/total ventricular weight ratios, whereas hearts from normal birds and birds with hepatosis did not. Two isolates of C. perfringens produced necrotic enteritis in experimental birds; an attempt to reproduce hepatosis with these isolates was unsuccessful. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7. PMID:17423489

Atlas-Based Ventricular Shape Analysis for Understanding Congenital Heart Disease.

PubMed

Farrar, Genevieve; Suinesiaputra, Avan; Gilbert, Kathleen; Perry, James C; Hegde, Sanjeet; Marsden, Alison; Young, Alistair A; Omens, Jeffrey H; McCulloch, Andrew D

2016-12-01

Congenital heart disease is associated with abnormal ventricular shape that can affect wall mechanics and may be predictive of long-term adverse outcomes. Atlas-based parametric shape analysis was used to analyze ventricular geometries of eight adolescent or adult single-ventricle CHD patients with tricuspid atresia and Fontans. These patients were compared with an "atlas" of non-congenital asymptomatic volunteers, resulting in a set of z-scores which quantify deviations from the control population distribution on a patient-by-patient basis. We examined the potential of these scores to: (1) quantify abnormalities of ventricular geometry in single ventricle physiologies relative to the normal population; (2) comprehensively quantify wall motion in CHD patients; and (3) identify possible relationships between ventricular shape and wall motion that may reflect underlying functional defects or remodeling in CHD patients. CHD ventricular geometries at end-diastole and end-systole were individually compared with statistical shape properties of an asymptomatic population from the Cardiac Atlas Project. Shape analysis-derived model properties, and myocardial wall motions between end-diastole and end-systole, were compared with physician observations of clinical functional parameters. Relationships between altered shape and altered function were evaluated via correlations between atlas-based shape and wall motion scores. Atlas-based shape analysis identified a diverse set of specific quantifiable abnormalities in ventricular geometry or myocardial wall motion in all subjects. Moreover, this initial cohort displayed significant relationships between specific shape abnormalities such as increased ventricular sphericity and functional defects in myocardial deformation, such as decreased long-axis wall motion. These findings suggest that atlas-based ventricular shape analysis may be a useful new tool in the management of patients with CHD who are at risk of impaired ventricular wall mechanics and chamber remodeling.

The Critical Role of Pulmonary Arterial Compliance in Pulmonary Hypertension

PubMed Central

Prins, Kurt W.; Pritzker, Marc R.; Scandurra, John; Volmers, Karl; Weir, E. Kenneth

2016-01-01

The normal pulmonary circulation is a low-pressure, high-compliance system. Pulmonary arterial compliance decreases in the presence of pulmonary hypertension because of increased extracellular matrix/collagen deposition in the pulmonary arteries. Loss of pulmonary arterial compliance has been consistently shown to be a predictor of increased mortality in patients with pulmonary hypertension, even more so than pulmonary vascular resistance in some studies. Decreased pulmonary arterial compliance causes premature reflection of waves from the distal pulmonary vasculature, leading to increased pulsatile right ventricular afterload and eventually right ventricular failure. Evidence suggests that decreased pulmonary arterial compliance is a cause rather than a consequence of distal small vessel proliferative vasculopathy. Pulmonary arterial compliance decreases early in the disease process even when pulmonary artery pressure and pulmonary vascular resistance are normal, potentially enabling early diagnosis of pulmonary vascular disease, especially in high-risk populations. With the recognition of the prognostic importance of pulmonary arterial compliance, its impact on right ventricular function, and its contributory role in the development and progression of distal small-vessel proliferative vasculopathy, pulmonary arterial compliance is an attractive target for the treatment of pulmonary hypertension. PMID:26848601

Periodic oscillation of intracranial pressure in ventricular dilation: a preliminary report.

PubMed

Kuchiwaki, H; Misu, N; Kageyama, N; Ishiguri, H; Takada, S

1987-12-01

Artificial pressure waves (PWs) were generated by manual inflation of a balloon in the trigonum of the lateral ventricle in seven adult mongrel dogs with normal cerebrospinal fluid (CSF) circulation. In 14 of 16 series of continuous appearances of artificial PWs, local shifts of the brain were successfully monitored using small strain-gauge sensors at the periventricular structures in these animals. Of the 14 series, 13 showed displacements of the periventricular structures, suggesting ventricular dilation. These results did not always correlate with macroscopic findings. They are thought to be due largely to periventricular oedemas and, in part, non-uniform dilations of the ventricles during PWs. We conclude that a water hammer formed by reflection of an increased pulse pressure of PWs at the site of CSF absorption causes a shift of CSF from the ventricle to the periventricular structures through the wall of the ventricle. This phenomenon appears amplified in patients with impaired CSF absorption. Thus, PWs have a pathological role in the progress of ventricular dilation in patients with normal pressure hydrocephalus.

L-carnitine supplementation decreases the left ventricular mass in patients undergoing hemodialysis.

PubMed

Sakurabayashi, Tai; Miyazaki, Shigeru; Yuasa, Yasuko; Sakai, Shinji; Suzuki, Masashi; Takahashi, Sachio; Hirasawa, Yoshihei

2008-06-01

Patients on long-term hemodialysis become deficient in carnitine and are frequently treated with carnitine supplementation to offset their renal anemia, lipid abnormality and cardiac dysfunction. The therapeutic value of carnitine supplementation on left ventricular hypertrophy (LVH) in patients with normal cardiac systolic function remains uncertain. The cardiac morphology and function of 10 patients given 10 mg/kg of L-carnitine orally, immediately after hemodialysis sessions 3 times per week for a 12-month period were compared with 10 untreated control patients. Using echocardiography, left ventricular fractional shortening (LVFS) and left ventricular mass index (LVMI) were measured before and after the study period. As a result, amounts of serum-free carnitine increased from 28.4+/-4.7 to 58.5+/-12.1 micromol/L. The LVMI decreased significantly from 151.8+/-21.2 to 134.0+/-16.0 g/m(2) in treated patients (p<0.01), yet the LVMI in untreated control patients did not change significantly (ie, from 153.3+/-28.2 to 167.1+/-43.1 g/m(2)). However, LVFS values remained unchanged in both groups. Although L-carnitine promoted a 31% reduction in erythropoietin requirements, hematocrit and blood pressure did not change during the study period. Supplementation with L-carnitine induced regression of LVH in patients on hemodialysis, even for those with normal systolic function.

Tachycardia, reduced vagal capacity, and age-dependent ventricular dysfunction arising from diminished expression of the presynaptic choline transporter

PubMed Central

English, Brett A.; Appalsamy, Martin; Diedrich, Andre; Ruggiero, Alicia M.; Lund, David; Wright, Jane; Keller, Nancy R.; Louderback, Katherine M.; Robertson, David

2010-01-01

Healthy cardiovascular function relies on a balanced and responsive integration of noradrenergic and cholinergic innervation of the heart. High-affinity choline uptake by cholinergic terminals is pivotal for efficient ACh production and release. To date, the cardiovascular impact of diminished choline transporter (CHT) expression has not been directly examined, largely due to the transporter's inaccessibility in vivo. Here, we describe findings from cardiovascular experiments using transgenic mice that bear a CHT genetic deficiency. Whereas CHT knockout (CHT−/−) mice exhibit early postnatal lethality, CHT heterozygous (CHT+/−) mice survive, grow, and reproduce normally and exhibit normal spontaneous behaviors. However, the CHT+/− mouse heart displays significantly reduced levels of high-affinity choline uptake accompanied by significantly reduced levels of ACh. Telemeterized recordings of cardiovascular function in these mice revealed tachycardia and hypertension at rest. After treadmill exercise, CHT+/− mice exhibited slower heart rate recovery, consistent with a diminished cholinergic reserve, a contention validated through direct vagal nerve stimulation. Echocardiographic and histological experiments revealed an age-dependent decrease in fractional shortening, increased left ventricular dimensions, and increased ventricular fibrosis, consistent with ventricular dysfunction. These cardiovascular phenotypes of CHT+/− mice encourage an evaluation of humans bearing reduced CHT expression for their resiliency in maintaining proper heart function as well as risk for cardiovascular disease. PMID:20601463

Extraction of the human cerebral ventricular system from MRI: inclusion of anatomical knowledge and clinical perspective

NASA Astrophysics Data System (ADS)

Aziz, Aamer; Hu, Qingmao; Nowinski, Wieslaw L.

2004-04-01

The human cerebral ventricular system is a complex structure that is essential for the well being and changes in which reflect disease. It is clinically imperative that the ventricular system be studied in details. For this reason computer assisted algorithms are essential to be developed. We have developed a novel (patent pending) and robust anatomical knowledge-driven algorithm for automatic extraction of the cerebral ventricular system from MRI. The algorithm is not only unique in its image processing aspect but also incorporates knowledge of neuroanatomy, radiological properties, and variability of the ventricular system. The ventricular system is divided into six 3D regions based on the anatomy and its variability. Within each ventricular region a 2D region of interest (ROI) is defined and is then further subdivided into sub-regions. Various strict conditions that detect and prevent leakage into the extra-ventricular space are specified for each sub-region based on anatomical knowledge. Each ROI is processed to calculate its local statistics, local intensity ranges of cerebrospinal fluid and grey and white matters, set a seed point within the ROI, grow region directionally in 3D, check anti-leakage conditions and correct growing if leakage occurs and connects all unconnected regions grown by relaxing growing conditions. The algorithm was tested qualitatively and quantitatively on normal and pathological MRI cases and worked well. In this paper we discuss in more detail inclusion of anatomical knowledge in the algorithm and usefulness of our approach from clinical perspective.

The pathophysiology of chronic noncommunicating hydrocephalus: lessons from continuous intracranial pressure monitoring and ventricular infusion testing.

PubMed

Eide, Per Kristian

2017-08-11

OBJECTIVE The pathophysiology of chronic noncommunicating hydrocephalus (ncHC) is poorly understood. This present study explored whether lessons about the pathophysiology of this clinical entity might be retrieved from results of overnight monitoring of pulsatile and static intracranial pressure (ICP) and ventricular infusion testing. METHODS The study cohort included adult patients (> 20 years of age) with chronic ncHC due to aqueductal stenosis in whom symptoms had lasted a minimum of 6 months. A reference cohort consisted of age- and sex-matched patients managed for communicating HC (cHC). Information about symptoms and clinical improvement following surgery was retrieved from a quality register, and results of overnight ICP recordings and ventricular infusion testing were retrieved from the hospital ICP database. RESULTS The cohort with ncHC consisted of 61 patients of whom 6 (10%) were managed conservatively, 34 (56%) by endoscopic third ventriculostomy (ETV), and 21 (34%) using ETV and subsequent shunt surgery. In patients responding to surgery, pulsatile ICP (mean ICP wave amplitude) was significantly increased to a similar magnitude in patients with ncHC and the reference cohort (cHC). Furthermore, intracranial compliance (ICC) was reduced in clinical responders. The results of ventricular infusion testing provided evidence that patients responding to ETV have impaired ventricular CSF absorption, while those requiring shunt placement after ETV present with impaired CSF absorption both in the intraventricular and extraventricular compartments. CONCLUSIONS The study may provide some lessons about the pathophysiology of chronic ncHC. First, increased pulsatile ICP and impaired ICC characterize patients with chronic ncHC who respond clinically to CSF diversion surgery, even though static ICP is not increased. Second, in patients responding clinically to ETV, impaired ventricular CSF absorption may be a key factor. Patients requiring shunt placement for clinical response appear to have both intraventricular and extraventricular CSF absorption failure. A subgroup of patients with ncHC due to aqueductal stenosis has normal ventricular CSF absorption and normal ICC and may not be in need of surgical CSF diversion.

Geographical distribution of reference value of aging people's left ventricular end systolic diameter based on the support vector regression.

PubMed

Han, Xiao; Ge, Miao; Dong, Jie; Xue, Ranying; Wang, Zixuan; He, Jinwei

2014-09-01

The aim of this paper is to analyze the geographical distribution of reference value of aging people's left ventricular end systolic diameter (LVDs), and to provide a scientific basis for clinical examination. The study is focus on the relationship between reference value of left ventricular end systolic diameter of aging people and 14 geographical factors, selecting 2495 samples of left ventricular end systolic diameter (LVDs) of aging people in 71 units of China, in which including 1620 men and 875 women. By using the Moran's I index to make sure the relationship between the reference values and spatial geographical factors, extracting 5 geographical factors which have significant correlation with left ventricular end systolic diameter for building the support vector regression, detecting by the method of paired sample t test to make sure the consistency between predicted and measured values, finally, makes the distribution map through the disjunctive kriging interpolation method and fits the three-dimensional trend of normal reference value. It is found that the correlation between the extracted geographical factors and the reference value of left ventricular end systolic diameter is quite significant, the 5 indexes respectively are latitude, annual mean air temperature, annual mean relative humidity, annual precipitation amount, annual range of air temperature, the predicted values and the observed ones are in good conformity, there is no significant difference at 95% degree of confidence. The overall trend of predicted values increases from west to east, increases first and then decreases from north to south. If geographical values are obtained in one region, the reference value of left ventricular end systolic diameter of aging people in this region can be obtained by using the support vector regression model. It could be more scientific to formulate the different distributions on the basis of synthesizing the physiological and the geographical factors. -Use Moran's index to analyze the spatial correlation. -Choose support vector machine to build model that overcome complexity of variables. -Test normal distribution of predicted data to guarantee the interpolation results. -Through trend analysis to explain the changes of reference value clearly. Copyright © 2014 Elsevier Inc. All rights reserved.

Heart monitoring using left ventricle impedance and ventricular electrocardiography in left ventricular assist device patients.

PubMed

Her, Keun; Ahn, Chi Bum; Park, Sung Min; Choi, Seong Wook

2015-03-21

Patients who develop critical arrhythmia during left ventricular assist device (LVAD) perfusion have a low survival rate. For diagnosis of unexpected heart abnormalities, new heart-monitoring methods are required for patients supported by LVAD perfusion. Ventricular electrocardiography using electrodes implanted in the ventricle to detect heart contractions is unsuitable if the heart is abnormal. Left ventricular impedance (LVI) is useful for monitoring heart movement but does not show abnormal action potential in the heart muscle. To detect detailed abnormal heart conditions, we obtained ventricular electrocardiograms (v-ECGs) and LVI simultaneously in porcine models connected to LVADs. In the porcine models, electrodes were set on the heart apex and ascending aorta for real-time measurements of v-ECGs and LVI. As the carrier current frequency of the LVI was adjusted to 30 kHz, it was easily derived from the original v-ECG signal by using a high-pass filter (cutoff: 10 kHz). In addition, v-ECGs with a frequency band of 0.1 - 120 Hz were easily derived using a low-pass filter. Simultaneous v-ECG and LVI data were compared to detect heart volume changes during the Q-T period when the heart contracted. A new real-time algorithm for comparison of v-ECGs and LVI determined whether the porcine heartbeats were normal or abnormal. Several abnormal heartbeats were detected using the LVADs operating in asynchronous mode, most of which were premature ventricle contractions (PVCs). To evaluate the accuracy of the new method, the results obtained were compared to normal ECG data and cardiac output measured simultaneously using commercial devices. The new method provided more accurate detection of abnormal heart movements. This method can be used for various heart diseases, even those in which the cardiac output is heavily affected by LVAD operation.

[Continuous registration of micropotentials of the human heart. Initial experiences with a new high resolution ECG amplifier system].

PubMed

Hombach, V; Kebbel, U; Höpp, H W; Winter, U J; Braun, V; Deutsch, H; Hirche, H; Hilger, H H

1982-12-24

A new ECG-amplifier system for recording cardiac microvolt potentials from the body surface is described. The improvement in signal-to-noise ratio was achieved by using specially designed suction electrodes, which were isolated from each other; by applying parallel signal averaging from four electrode pairs via four low-noise amplifiers; and by conducting the registration in Faraday cage. in 14 normal subjects, 12 patients with coronary heart disease and one patient with surgically corrected ventricular septal defect and pulmonary stenosis, pre-P-potentials (possible sinus node activity), His bundle potentials and ventricular late potentials were recorded with differing degrees of success. Variations of the time intervals to the preceding QRS complex were observed within the S-T segment in six of nine patients with demonstrable ventricular late ventricular late potentials. The advantage of such continuously recording ECG system lies in the highly accurate registration of cardiac micropotentials, particularly with ventricular late potentials that are changing in time, whereas the signal-averaging technique does not provide such possibilities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanton, M.S.; Tuli, M.M.; Radtke, N.L.

Transmural myocardial infarction in dogs produces denervation of sympathetic nerves in viable myocardium apical to the infarct that may be arrhythmogenic. It is unknown whether sympathetic denervation occurs in humans. The purpose of this study was to use iodine-123-metaiodobenzylguanidine (MIBG), a radiolabeled guanethidine analog that is actively taken up by sympathetic nerve terminals, to image noninvasively the cardiac sympathetic nerves in patients with and without ventricular arrhythmias after myocardial infarction. Results showed that 10 of 12 patients with spontaneous ventricular tachyarrhythmias after myocardial infarction exhibited regions of thallium-201 uptake indicating viable perfused myocardium, with no MIBG uptake. Such a findingmore » is consistent with sympathetic denervation. One patient had frequent episodes of nonsustained ventricular tachycardia induced at exercise testing that was eliminated by beta-adrenoceptor blockade. Eleven of the 12 patients had ventricular tachycardia induced at electrophysiologic study and metoprolol never prevented induction. Sympathetic denervation was also detected in two of seven postinfarction patients without ventricular arrhythmias. Normal control subjects had no regions lacking MIBG uptake. This study provides evidence that regional sympathetic denervation occurs in humans after myocardial infarction and can be detected noninvasively by comparing MIBG and thallium-201 images. Although the presence of sympathetic denervation may be related to the onset of spontaneous ventricular tachyarrhythmias in some patients, it does not appear to be related to sustained ventricular tachycardia induced at electrophysiologic study.« less

Echocardiographic Classification and Surgical Approaches to Double-Outlet Right Ventricle for Great Arteries Arising Almost Exclusively from the Right Ventricle.

PubMed

Pang, Kun-Jing; Meng, Hong; Hu, Sheng-Shou; Wang, Hao; Hsi, David; Hua, Zhong-Dong; Pan, Xiang-Bin; Li, Shou-Jun

2017-08-01

Selecting an appropriate surgical approach for double-outlet right ventricle (DORV), a complex congenital cardiac malformation with many anatomic variations, is difficult. Therefore, we determined the feasibility of using an echocardiographic classification system, which describes the anatomic variations in more precise terms than the current system does, to determine whether it could help direct surgical plans. Our system includes 8 DORV subtypes, categorized according to 3 factors: the relative positions of the great arteries (normal or abnormal), the relationship between the great arteries and the ventricular septal defect (committed or noncommitted), and the presence or absence of right ventricular outflow tract obstruction (RVOTO). Surgical approaches in 407 patients were based on their DORV subtype, as determined by echocardiography. We found that the optimal surgical management of patients classified as normal/committed/no RVOTO, normal/committed/RVOTO, and abnormal/committed/no RVOTO was, respectively, like that for patients with large ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries without RVOTO. Patients with abnormal/committed/RVOTO anatomy and those with abnormal/noncommitted/RVOTO anatomy underwent intraventricular repair and double-root translocation. For patients with other types of DORV, choosing the appropriate surgical approach and biventricular repair techniques was more complex. We think that our classification system accurately groups DORV patients and enables surgeons to select the best approach for each patient's cardiac anatomy.

Preoperative left ventricular internal dimension in end-diastole as earlier identification of early patent ductus arteriosus operation and postoperative intensive care in very low birth weight infants.

PubMed

Saida, Ken; Nakamura, Tomohiko; Hiroma, Takehiko; Takigiku, Kiyohiro; Yasukochi, Satoshi

2013-10-01

Patent ductus arteriosus (PDA) is common in premature infants. In very low birth weight infants (VLBWI), PDA requires surgical therapy in many cases. It is unclear to know at-risk infants showing cardio-dysfunction after PDA surgery. The purpose of this study was to identify at-risk infants showing cardio-dysfunction after surgery for patent ductus arteriosus (PDA). We examined the relationship between left ventricular (LV) performance before and after PDA ligation in a retrospective observational cohort study. We studied 64 preterm neonates with symptomatic PDA before and after surgical ligation. Echocardiographic examinations were performed pre- and postoperatively. M-mode measurements included left ventricular internal dimension in end-diastole (LVIDd) and LV fractional shortening (FS). All cases showed decreased LVFS after PDA closure. Most cases (49/64, 77%) showed postoperative FS decreased to below normal (<28%). Preoperative relative LVIDd was significantly larger in abnormal FS infants (137 ± 18%) than in normal FS infants (118 ± 11%; p<0.01). A cut-off value of preoperative relative LVIDd (absolute LVIDd/normal value) for predicting postoperative cardio-dysfunction was 127.4% (sensitivity, 0.735; specificity, 0.933; area under curve, 0.817). Determination of preoperative LVIDd might facilitate earlier identification of infants needing early PDA surgery and postoperative intensive care. © 2013 Elsevier Ireland Ltd. All rights reserved.

Association of Apical Longitudinal Rotation with Right Ventricular Performance in Patients with Pulmonary Hypertension: Insights into Overestimation of Tricuspid Annular Plane Systolic Excursion.

PubMed

Motoji, Yoshiki; Tanaka, Hidekazu; Fukuda, Yuko; Sano, Hiroyuki; Ryo, Keiko; Sawa, Takuma; Miyoshi, Tatsuya; Imanishi, Junichi; Mochizuki, Yasuhide; Tatsumi, Kazuhiro; Matsumoto, Kensuke; Emoto, Noriaki; Hirata, Ken-ichi

2016-02-01

Current guidelines recommend the routine use of tricuspid annular plane systolic excursion (TAPSE) as a simple method for estimating right ventricular (RV) function. However, when ventricular apical longitudinal rotation (apical-LR) occurs in pulmonary hypertension (PH) patients, it may result in overestimated TAPSE. We studied 105 patients with PH defined as mean pulmonary artery pressure >25 mmHg at rest measured by right heart cardiac catheterization. TAPSE was defined as the maximum displacement during systole in the RV-focused apical four-chamber view. RV free-wall longitudinal speckle tracking strain (RV-free) was calculated by averaging 3 regional peak systolic strains. The apical-LR was measured at the peak rotation in the apical region including both left and right ventricle. The eccentricity index (EI) was defined as the ratio of the length of 2 perpendicular minor-axis diameters, one of which bisected and was perpendicular to the interventricular septum, and was obtained at end-systole (EI-sys) and end-diastole (EI-dia). Twenty age-, gender-, and left ventricular ejection fraction-matched normal controls were studied for comparison. The apical-LR in PH patients was significantly lower than that in normal controls (-3.4 ± 2.7° vs. -1.3 ± 1.9°, P = 0.001). Simple linear regression analysis showed that gender, TAPSE, EI-sys, and EI-dia/EI-sys were associated with apical-LR, but RV-free was not. Multiple regression analysis demonstrated that gender, EI-dia/EI-sys, and TAPSE were independent determinants of apical-LR. TAPSE may be overestimated in PH patients with clockwise rotation resulting from left ventricular compression. TAPSE should thus be evaluated carefully in PH patients with marked apical rotation. © 2015, Wiley Periodicals, Inc.

Assessment of tenascin-C levels in ventricular noncompaction/hypertrabeculation patients: a cross-sectional study.

PubMed

Erer, Hatice Betul; Guvenc, Tolga Sinan; Kemik, Ahu Sarbay; Yilmaz, Hale; Kul, Seref; Altay, Servet; Oz, Dilaver; Zeren, Gonul; Ekmekci, Ahmet; Zencirci, Aycan Esen; Sayar, Nurten; Eren, Mehmet

2014-02-01

Ventricular noncompaction/hypertrabeculation (NC/HT) is a rare form of congenital cardiomyopathy. We aimed to investigate the presence of serum tenascin-C (TN-C) in adult patients with NC/HT and evaluate its value. Serum TN-C levels were measured by ELISA in 50 NC/HT patients both with/without systolic dysfunction and in 23 normal controls. Systolic dysfunction was defined as ejection fraction (EF) ≤ 40. Mann-Whitney U-test and ROC curve analysis were done. Of 49 NC/HT patients, 24 (49%) patients had systolic dysfunction (mean age 36 ± 15) and 25 patients (51%) had normal systolic function (mean age 36 ± 17). The ages between groups were not different. The mean levels of serum TN-C in patients with or without systolic dysfunction were 26 ± 10 ng/mL and 26 ± 8 ng/mL respectively, compared to normal controls, 7 ± 2 ng/mL (P < 0.001). No significance was observed between 2 groups of NC/HT patients regarding TN-C levels (P = 0.8). The ROC curve analysis revealed that a TN-C value of 11.7 ng/mL identified patients with NC/HT with 100% sensitivity and specifity. High serum TN-C levels are present in adult NC/HT cardiomyopathy even when left ventricular systolic function remains normal. Also, serum TN-C levels could be regarded as a candidate biomarker in the diagnosis of NC/HT which needs to be tested in larger prospective studies. © 2013, Wiley Periodicals, Inc.

Afterload mismatch in aortic and mitral valve disease: implications for surgical therapy.

PubMed

Ross, J

1985-04-01

In the management of patients with valvular heart disease, an understanding of the effects of altered loading conditions on the left ventricle is important in reaching a proper decision concerning the timing of corrective operation. In acquired valvular aortic stenosis, concentric hypertrophy generally maintains left ventricular chamber size and ejection fraction within normal limits, but in late stage disease function can deteriorate as preload reserve is lost and aortic stenosis progresses. In this setting, even when the ejection fraction is markedly reduced (less than 25%), it can improve to normal after aortic valve replacement, suggesting that afterload mismatch rather than irreversibly depressed myocardial contractility was responsible for left ventricular failure. Therefore, patients with severe aortic stenosis and symptoms should not be denied operation because of impaired cardiac function. In chronic severe aortic and mitral regurgitation, operation is generally recommended when symptoms are present, but whether to recommend operation to prevent irreversible myocardial damage in patients with few or no symptoms has remained controversial. In aortic regurgitation, left ventricular function generally improves postoperatively, even if it is moderately impaired preoperatively, indicating correction of afterload mismatch. Most such patients can be carefully followed by echocardiography. However, in some patients, severe left ventricular dysfunction fails to improve postoperatively. Therefore, when echocardiographic studies in the patient with severe aortic regurgitation show an ejection fraction of less than 40% (fractional shortening less than 25%) plus enlarging left ventricular end-diastolic diameter (approaching 38 mm/m2 body surface area) and end-systolic diameter (approaching 50 mm or 26 mm/m2), confirmation of these findings by cardiac catheterization and consideration of operation are advisable even in patients with minimal symptoms. In chronic mitral regurgitation, maintenance of a normal ejection fraction can mask depressed myocardial contractility. Pre- and postoperative studies in such patients have shown a poor clinical result after mitral valve replacement, associated with a sharp decrease in the ejection fraction after operation. This response appears to reflect unmasking of decreased myocardial contractility by mitral valve replacement, with ejection of the total stroke volume into the high impedance of the aorta (afterload mismatch produced by operation).(ABSTRACT TRUNCATED AT 400 WORDS)

Device Management and Flow Optimization on Left Ventricular Assist Device Support.

PubMed

Tchoukina, Inna; Smallfield, Melissa C; Shah, Keyur B

2018-07-01

The authors discuss principles of continuous flow left ventricular assist device (LVAD) operation, basic differences between the axial and centrifugal flow designs and hemodynamic performance, normal LVAD physiology, and device interaction with the heart. Systematic interpretation of LVAD parameters and recognition of abnormal patterns of flow and pulsatility on the device interrogation are necessary for clinical assessment of the patient. Optimization of pump flow using LVAD parameters and echocardiographic and hemodynamics guidance are reviewed. Copyright © 2018 Elsevier Inc. All rights reserved.

Determination of right ventricular ejection fraction in children with cystic fibrosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piepsz, A.; Ham, H.R.; Millet, E.

1987-01-01

The radionuclide right ventricular ejection fraction (RVEF) determined by means of Krypton-81m represents a simple, noninvasive, and accurate procedure to quantify the right ventricular contractility. This procedure was applied to 25 young patients with cystic fibrosis. The RVEF tended to decrease with the progression of the lung disease, as assessed by the clinical S-K score, the degree of the defects on lung scintigraphy, the PaO/sub 2/, and the lung function tests. However, the decrease of RVEF in patients with marked lung function tests. However, the decrease of RVEF in patients with marked lung involvement was moderate, and terminal lung diseasemore » was sometimes associated with normal right heart contractility.« less

Myoarchitecture and connective tissue in hearts with tricuspid atresia

PubMed Central

Sanchez-Quintana, D; Climent, V; Ho, S; Anderson, R

1999-01-01

Objective—To compare the atrial and ventricular myoarchitecture in the normal heart and the heart with tricuspid atresia, and to investigate changes in the three dimensional arrangement of collagen fibrils.
Methods—Blunt dissection and cell maceration with scanning electron microscopy were used to study the architecture of the atrial and ventricular musculature and the arrangement of collagen fibrils in three specimens with tricuspid atresia and six normal human hearts.
Results—There were significant modifications in the myoarchitecture of the right atrium and the left ventricle, both being noticeably hypertrophied. The middle layer of the ventricle in the abnormal hearts was thicker than in the normal hearts. The orientation of the superficial layer in the left ventricle in hearts with tricuspid atresia was irregular compared with the normal hearts. Scanning electron microscopy showed coarser endomysial sheaths and denser perimysial septa in hearts with tricuspid atresia than in normal hearts.
Conclusions—The overall architecture of the muscle fibres and its connective tissue matrix in hearts with tricuspid atresia differed from normal, probably reflecting modelling of the myocardium that is inherent to the malformation. This is in concordance with clinical observations showing deterioration in pump function of the dominant left ventricle from very early in life.

 Keywords: tricuspid atresia; congenital heart defects; connective tissue; fibrosis PMID:9922357

Coupling of a 3D Finite Element Model of Cardiac Ventricular Mechanics to Lumped Systems Models of the Systemic and Pulmonic Circulation

PubMed Central

Kerckhoffs, Roy C. P.; Neal, Maxwell L.; Gu, Quan; Bassingthwaighte, James B.; Omens, Jeff H.; McCulloch, Andrew D.

2010-01-01

In this study we present a novel, robust method to couple finite element (FE) models of cardiac mechanics to systems models of the circulation (CIRC), independent of cardiac phase. For each time step through a cardiac cycle, left and right ventricular pressures were calculated using ventricular compliances from the FE and CIRC models. These pressures served as boundary conditions in the FE and CIRC models. In succeeding steps, pressures were updated to minimize cavity volume error (FE minus CIRC volume) using Newton iterations. Coupling was achieved when a predefined criterion for the volume error was satisfied. Initial conditions for the multi-scale model were obtained by replacing the FE model with a varying elastance model, which takes into account direct ventricular interactions. Applying the coupling, a novel multi-scale model of the canine cardiovascular system was developed. Global hemodynamics and regional mechanics were calculated for multiple beats in two separate simulations with a left ventricular ischemic region and pulmonary artery constriction, respectively. After the interventions, global hemodynamics changed due to direct and indirect ventricular interactions, in agreement with previously published experimental results. The coupling method allows for simulations of multiple cardiac cycles for normal and pathophysiology, encompassing levels from cell to system. PMID:17111210

Ventriculostomy Simulation Using Patient-Specific Ventricular Anatomy, 3D Printing, and Hydrogel Casting.

PubMed

Ryan, Justin R; Chen, Tsinsue; Nakaji, Peter; Frakes, David H; Gonzalez, L Fernando

2015-11-01

Educational simulators provide a means for students and experts to learn and refine surgical skills. Educators can leverage the strengths of medical simulators to effectively teach complex and high-risk surgical procedures, such as placement of an external ventricular drain. Our objective was to develop a cost-effective, patient-derived medical simulacrum for cerebral lateral ventriculostomy. A cost-effective, patient-derived medical simulacrum was developed for placement of an external lateral ventriculostomy. Elastomeric and gel casting techniques were used to achieve realistic brain geometry and material properties. 3D printing technology was leveraged to develop accurate cranial properties and dimensions. An economical, gravity-driven pump was developed to provide normal and abnormal ventricular pressures. A small pilot study was performed to gauge simulation efficacy using a technology acceptance model. An accurate geometric representation of the brain was developed with independent lateral cerebral ventricular chambers. A gravity-driven pump pressurized the ventricular cavities to physiologic values. A qualitative study illustrated that the simulation has potential as an educational tool to train medical professionals in the ventriculostomy procedure. The ventricular simulacrum can improve learning in a medical education environment. Rapid prototyping and multi-material casting techniques can produce patient-derived models for cost-effective and realistic surgical training scenarios. Copyright © 2015 Elsevier Inc. All rights reserved.

Predicting the risk of sudden cardiac death.

PubMed

Lerma, Claudia; Glass, Leon

2016-05-01

Sudden cardiac death (SCD) is the result of a change of cardiac activity from normal (typically sinus) rhythm to a rhythm that does not pump adequate blood to the brain. The most common rhythms leading to SCD are ventricular tachycardia (VT) or ventricular fibrillation (VF). These result from an accelerated ventricular pacemaker or ventricular reentrant waves. Despite significant efforts to develop accurate predictors for the risk of SCD, current methods for risk stratification still need to be improved. In this article we briefly review current approaches to risk stratification. Then we discuss the mathematical basis for dynamical transitions (called bifurcations) that may lead to VT and VF. One mechanism for transition to VT or VF involves a perturbation by a premature ventricular complex (PVC) during sinus rhythm. We describe the main mechanisms of PVCs (reentry, independent pacemakers and abnormal depolarizations). An emerging approach to risk stratification for SCD involves the development of individualized dynamical models of a patient based on measured anatomy and physiology. Careful analysis and modelling of dynamics of ventricular arrhythmia on an individual basis will be essential in order to improve risk stratification for SCD and to lay a foundation for personalized (precision) medicine in cardiology. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Recurrent Ventricular Tachycardia in Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency.

PubMed

Bala, P; Ferdinandusse, S; Olpin, S E; Chetcuti, P; Morris, A A M

2016-01-01

We report a baby with medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency who presented on day 2 with poor feeding and lethargy. She was floppy with hypoglycaemia (1.8 mmol/l) and hyperammonaemia (182 μmol/l). Despite correction of these and a continuous intravenous infusion of glucose at 4.5-6.2 mg/kg/min, she developed generalised tonic clonic seizures on day 3. She also suffered two episodes of pulseless ventricular tachycardia, from which she was resuscitated successfully. Unfortunately, she died on day 5, following a third episode of pulseless ventricular tachycardia. Arrhythmias are generally thought to be rarer in MCAD deficiency than in disorders of long-chain fatty acid oxidation. This is, however, the sixth report of ventricular tachyarrhythmias in MCAD deficiency. Five of these involved neonates and it may be that patients with MCAD deficiency are particularly prone to ventricular arrhythmias in the newborn period. Three of the patients (including ours) had normal blood glucose concentrations at the time of the arrhythmias and had been receiving intravenous glucose for many hours. These cases suggest that arrhythmias can be induced by medium-chain acylcarnitines or other metabolites accumulating in MCAD deficiency. Ventricular tachyarrhythmias can occur in MCAD deficiency, especially in neonates.

Echocardiographic features of impaired left ventricular diastolic function in Chagas's heart disease.

PubMed Central

Combellas, I; Puigbo, J J; Acquatella, H; Tortoledo, F; Gomez, J R

1985-01-01

To study left ventricular diastolic function in Chagas's disease, simultaneous echocardiograms, phonocardiograms, and apexcardiograms were recorded in 20 asymptomatic patients with positive Chagas's serology and no signs of heart disease (group 1), 12 with Chagas's heart disease and symptoms of ventricular arrhythmia but no heart failure (group 2), 20 normal subjects (group 3), and 12 patients with left ventricular hypertrophy (group 4). The recordings were digitised to determine left ventricular isovolumic relaxation time and the rate and duration of left ventricular cavity dimension increase and wall thinning. In groups 1 and 2 (a) aortic valve closure (A2) and mitral valve opening were significantly delayed relative to minimum dimension and were associated with prolonged isovolumic relaxation, (b) left ventricular cavity size was abnormally increased during isovolumic relaxation and abnormally reduced during isovolumic contraction, and (c) peak rate of posterior wall thinning and dimension increase were significantly reduced and duration of posterior wall thinning was significantly prolonged; both of these abnormalities occurred at the onset of diastolic filling. These abnormalities were more pronounced in group 2 and were accompanied by an increase in the height of the apexcardiogram "a" wave, an indication of pronounced atrial systole secondary to end diastolic filling impairment due to reduced left ventricular distensibility. Group 4, which had an established pattern of diastolic abnormalities, showed changes similar to those in group 2; however, the delay in aortic valve closure (A2) and in mitral valve opening and the degree of dimension change were greater in the latter group. Thus early isovolumic relaxation and left ventricular abnormalities were pronounced in the patients with Chagas's heart disease and may precede systolic compromise, which may become apparent in later stages of the disease. The digitised method is valuable in the early detection of myocardial damage. Images PMID:3155954

Studying ventricular abnormalities in mild cognitive impairment with hyperbolic Ricci flow and tensor-based morphometry.

PubMed

Shi, Jie; Stonnington, Cynthia M; Thompson, Paul M; Chen, Kewei; Gutman, Boris; Reschke, Cole; Baxter, Leslie C; Reiman, Eric M; Caselli, Richard J; Wang, Yalin

2015-01-01

Mild Cognitive Impairment (MCI) is a transitional stage between normal aging and dementia and people with MCI are at high risk of progression to dementia. MCI is attracting increasing attention, as it offers an opportunity to target the disease process during an early symptomatic stage. Structural magnetic resonance imaging (MRI) measures have been the mainstay of Alzheimer's disease (AD) imaging research, however, ventricular morphometry analysis remains challenging because of its complicated topological structure. Here we describe a novel ventricular morphometry system based on the hyperbolic Ricci flow method and tensor-based morphometry (TBM) statistics. Unlike prior ventricular surface parameterization methods, hyperbolic conformal parameterization is angle-preserving and does not have any singularities. Our system generates a one-to-one diffeomorphic mapping between ventricular surfaces with consistent boundary matching conditions. The TBM statistics encode a great deal of surface deformation information that could be inaccessible or overlooked by other methods. We applied our system to the baseline MRI scans of a set of MCI subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI: 71 MCI converters vs. 62 MCI stable). Although the combined ventricular area and volume features did not differ between the two groups, our fine-grained surface analysis revealed significant differences in the ventricular regions close to the temporal lobe and posterior cingulate, structures that are affected early in AD. Significant correlations were also detected between ventricular morphometry, neuropsychological measures, and a previously described imaging index based on fluorodeoxyglucose positron emission tomography (FDG-PET) scans. This novel ventricular morphometry method may offer a new and more sensitive approach to study preclinical and early symptomatic stage AD. Copyright © 2014 Elsevier Inc. All rights reserved.

Autoantibodies against β1 receptor and AT1 receptor in type 2 diabetes patients with left ventricular dilatation.

PubMed

Zhao, Linshuang; Xu, Chunyan; Xu, Jinling

2014-01-01

To explore the relationship between the autoantibodies against the β1 and AT1 receptors and left ventricular dilatation in patients with type 2 diabetes (T2DM). The autoantibodies against the β1 and angiotensin II type 1 (AT1) receptors of T2DM patients with and without hypertension were screened by ELISA. Multiple logistic regression was used to analyze the risk factors for left ventricular dilatation. The reversing effect of left ventricular dilatation was evaluated after receptor blocker treatment. The positive rates of autoantibodies against the β1 and AT1 receptors (43.0 and 44.1%, respectively) in T2DM patients with hypertension were significantly higher than those in normotensive patients (16.0 and 10.4%, respectively; all p < 0.01). Furthermore, among T2DM patients with hypertension, the positive rates (61.4 and 64.9%, respectively) in patients with left ventricular dilatation were remarkably higher than those with normal left ventricular dimensions (34.4 and 36.1%, respectively; all p < 0.01). The presence of β1 receptor antibody and AT1 receptor antibody were risk factors for left ventricular dilatation (p < 0.05). The curative effect of metoprolol tartrate and valsartan in reversing left ventricular hypertrophy in the group positive for autoantibodies was much better than in the negative group. The findings show that autoantibodies against the β1 and AT1 receptors may play a role in predicting left ventricular dilatation in T2DM patients in combination with hypertension. Metoprolol tartrate and valsartan are effective and safe in the treatment of these patients. © 2014 S. Karger AG, Basel.

STUDYING VENTRICULAR ABNORMALITIES IN MILD COGNITIVE IMPAIRMENT WITH HYPERBOLIC RICCI FLOW AND TENSOR-BASED MORPHOMETRY

PubMed Central

Shi, Jie; Stonnington, Cynthia M.; Thompson, Paul M.; Chen, Kewei; Gutman, Boris; Reschke, Cole; Baxter, Leslie C.; Reiman, Eric M.; Caselli, Richard J.; Wang, Yalin

2014-01-01

Mild Cognitive Impairment (MCI) is a transitional stage between normal aging and dementia and people with MCI are at high risk of progression to dementia. MCI is attracting increasing attention, as it offers an opportunity to target the disease process during an early symptomatic stage. Structural magnetic resonance imaging (MRI) measures have been the mainstay of Alzheimer’s disease (AD) imaging research, however, ventricular morphometry analysis remains challenging because of its complicated topological structure. Here we describe a novel ventricular morphometry system based on the hyperbolic Ricci flow method and tensor-based morphometry (TBM) statistics. Unlike prior ventricular surface parameterization methods, hyperbolic conformal parameterization is angle-preserving and does not have any singularities. Our system generates a one-to-one diffeomorphic mapping between ventricular surfaces with consistent boundary matching conditions. The TBM statistics encode a great deal of surface deformation information that could be inaccessible or overlooked by other methods. We applied our system to the baseline MRI scans of a set of MCI subjects from the Alzheimer’s Disease Neuroimaging Initiative (ADNI: 71 MCI converters vs. 62 MCI stable). Although the combined ventricular area and volume features did not differ between the two groups, our fine-grained surface analysis revealed significant differences in the ventricular regions close to the temporal lobe and posterior cingulate, structures that are affected early in AD. Significant correlations were also detected between ventricular morphometry, neuropsychological measures, and a previously described imaging index based on fluorodeoxyglucose positron emission tomography (FDG-PET) scans. This novel ventricular morphometry method may offer a new and more sensitive approach to study preclinical and early symptomatic stage AD. PMID:25285374

Radionuclide evaluation of left-ventricular function in chronic Chagas' cardiomyopathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arreaza, N.; Puigbo, J.J.; Acquatella, H. Casal, H.

1983-07-01

Left-ventricular ejection fraction (LVEF) and abnormalities of regional wall motion (WMA) were studied by means of radionuclide ventriculography in 41 patients prospectively diagnosed as having chronic Chagas' disease. Thirteen patients were asymptomatic (ASY), 16 were arrhythmic (ARR), and 12 had congestive heart failure (CHF). Mean LVEF was normal in ASY but markedly depressed in CHF. Regional WMAs were minimal in ASY and their severity increased in ARR. Most CHFs (75%) had diffuse hypokinesia of the left ventricle. Seven patients had a distinct apical aneurysm. Correlation between radionuclide and contrast ventriculography data was good in 17 patients. Selective coronary arteriography showedmore » normal arteries in all patients. Therefore, chronic Chagas' heart disease joins ischemic heart disease as a cause of regional WMA.« less

Acetylcholine and choline in cerebrospinal fluid of patients with Parkinson's disease and Huntington's chorea.

PubMed Central

Welch, M J; Markham, C H; Jenden, D J

1976-01-01

Lumbar cerebrospinal fluid (CSF) acetylcholine (ACh) and choline (Ch) levels were measured in patients with Huntington's chorea (N=11), Parkinson's disease (N=8), and subjects at risk for Huntington's chorea (N=4), and all three groups were found not to differ significantly from normal controls (N=10). The values found for lumbar CSF ACh and Ch levels in the normal subjects were comparable with previously reported values. The use of physostigmine, a cholinesterase inhibitor, in collecting the CSF samples did not appear to make a difference with regard to ACh and Ch concentrations. Evidence suggesting a ventricular-lumbar gradient, with lumbar CSF Ch concentration being less than ventricular CSF Ch concentration, was found. Finally, ACh levels in CSF did not correlate with corresponding Ch levels. PMID:132512

Premature Ventricular Contractions (PVCs)

MedlinePlus

... This natural pacemaker produces the electrical impulses that trigger the normal heartbeat. From the sinus node, electrical ... occur? The reasons aren't always clear. Certain triggers, heart diseases or changes in the body can ...

[Effects of trimetazidine on serum oxygen free radicals in congestive heart failure].

PubMed

Ma, Qi-lin; Xie, Yong; Zhang, Sai-dan

2002-12-28

To investigate the level of serum superoxide dismutase (SOD) and maiondialdehyde (MDA) and left ventricular systolic function in congestive heart failure (CHF) and to evaluate the influence of trimetazidine on them. Serum SOD and MDA were measured in 50 patients with heart function from grade two to four and 15 normal subjects. All the persons underwent echocardiography to determine the left ventricular end-systolic volume index (LVESVI) and the left ventricular ejection fraction (EF). The patients with CHF were randomly treated with trimetazidine plus routine therapy (n = 25) or routine therapy only (n = 25) for 8 weeks with evaluations made before and after the treatment. The SOD level and EF in the patients with CHF significantly decreased and the MDA level and LVESVI in those patients significantly increased compared with the normal subjects (P < 0.05); the severer the CHF, the greater the changes. After the treatment, the SOD level and EF increased significantly and MDA and LVESVI decreased significantly (P < 0.01) in both the trimetazidine and the conventional groups. And these changes were more obvious in the trimetazidine group than in the conventional group(P < 0.01). Oxygen free radicals play an important role in the pathophysiologic changes of CHF. The level of serum SOD and MDA can indicate the degree of CHF. Trimetazidine not only increases the level of SOD and decreases the level of MDA, but also improves the left ventricular systolic function.

Low Transvalvular Flow Rate Predicts Mortality in Patients With Low-Gradient Aortic Stenosis Following Aortic Valve Intervention.

PubMed

Vamvakidou, Anastasia; Jin, Wenying; Danylenko, Oleksandr; Chahal, Navtej; Khattar, Rajdeep; Senior, Roxy

2018-03-09

This study aimed to assess the value of low transvalvular flow rate (FR) for the prediction of mortality compared with low stroke volume index (SVi) in patients with low-gradient (mean gradient: <40 mm Hg), low aortic valve area (<1 cm 2 ) aortic stenosis (AS) following aortic valve intervention. Transaortic FR defined as stroke volume/left ventricular ejection time is also a marker of flow; however, no data exist comparing the relative prognostic value of these 2 transvalvular flow markers in patients with low-gradient AS who had undergone valve intervention. We retrospectively followed prospectively assessed consecutive patients with low-gradient, low aortic valve area AS who underwent aortic valve intervention between 2010 and 2014 for all-cause mortality. Of the 218 patients with mean age 75 ± 12 years, 102 (46.8%) had low stroke volume index (SVi) (<35 ml/m 2 ), 95 (43.6%) had low FR (<200 ml/s), and 58 (26.6%) had low left ventricular ejection fraction <50%. The concordance between FR and SVi was 78.8% (p < 0.005). Over a median follow-up of 46.8 ± 21 months, 52 (23.9%) deaths occurred. Patients with low FR had significantly worse outcome compared with those with normal FR (p < 0.005). In patients with low SVi, a low FR conferred a worse outcome than a normal FR (p = 0.005), but FR status did not discriminate outcome in patients with normal SVi. By contrast, SVi did not discriminate survival either in patients with normal or low FR. Low FR was an independent predictor of mortality (p = 0.013) after adjusting for age, clinical prognostic factors, European System for Cardiac Operative Risk Evaluation II, dimensionless velocity index, left ventricular mass index, left ventricular ejection fraction, heart rate, time, type of aortic valve intervention, and SVi (p = 0.59). In patients with low-gradient, low valve area aortic stenosis undergoing aortic valve intervention, low FR, not low SVi, was an independent predictor of medium-term mortality. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Targeted deletion of apoptosis signal-regulating kinase 1 attenuates left ventricular remodeling

PubMed Central

Yamaguchi, Osamu; Higuchi, Yoshiharu; Hirotani, Shinichi; Kashiwase, Kazunori; Nakayama, Hiroyuki; Hikoso, Shungo; Takeda, Toshihiro; Watanabe, Tetsuya; Asahi, Michio; Taniike, Masayuki; Matsumura, Yasushi; Tsujimoto, Ikuko; Hongo, Kenichi; Kusakari, Yoichiro; Kurihara, Satoshi; Nishida, Kazuhiko; Ichijo, Hidenori; Hori, Masatsugu; Otsu, Kinya

2003-01-01

Left ventricular remodeling that occurs after myocardial infarction (MI) and pressure overload is generally accepted as a determinant of the clinical course of heart failure. The molecular mechanism of this process, however, remains to be elucidated. Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase kinase kinase that plays an important role in stress-induced apoptosis. We used ASK1 knockout mice (ASK-/-) to test the hypothesis that ASK1 is involved in development of left ventricular remodeling. ASK-/- hearts showed no morphological or histological defects. Echocardiography and cardiac catheterization revealed normal global structure and function. Left ventricular structural and functional remodeling were determined 4 weeks after coronary artery ligation or thoracic transverse aortic constriction (TAC). ASK-/- had significantly smaller increases in left ventricular end-diastolic and end-systolic ventricular dimensions and smaller decreases in fractional shortening in both experimental models compared with WT mice. The number of terminal deoxynucleotidyl transferase biotin-dUDP nick end-labeling-positive myocytes after MI or TAC was decreased in ASK-/- compared with that in WT mice. Overexpression of a constitutively active mutant of ASK1 induced apoptosis in isolated rat neonatal cardiomyocytes, whereas neonatal ASK-/- cardiomyocytes were resistant to H2O2-induced apoptosis. An in vitro kinase assay showed increased ASK1 activity in heart after MI or TAC in WT mice. Thus, ASK1 plays an important role in regulating left ventricular remodeling by promoting apoptosis. PMID:14665690

Cardiovascular studies using the chimpanzee (Pan troglodytes)

NASA Technical Reports Server (NTRS)

Hinds, J. E.; Cothran, L. N.; Hawthorne, E. W.

1977-01-01

Despite the phylogenetic similarities between chimpanzees and man, there exists a paucity of reliable data on normal cardiovascular function and the physiological responses of the system to standard interventions. Totally implanted biotelemetry systems or hardwire analog techniques were used to examine the maximum number of cardiovascular variables which could be simultaneously monitored without significantly altering the system's performance. This was performed in order to acquire base-line data not previously obtained in this species, to determine cardiovascular response to specific forcing functions such as ventricular pacing, drug infusions, and lower body negative pressure. A cardiovascular function profile protocol was developed in order to adjust independently the three major factors which modify ventricular performance, namely, left ventricular performance, left ventricular preload, afterload, and contractility. Cardiac pacing at three levels above the ambient rate was used to adjust end diastolic volume (preload). Three concentrations of angiotensin were infused continuously to evaluate afterload in a stepwide fashion. A continuous infusion of dobutamine was administered to raise the manifest contractile state of the heart.

[Corrected transposition of the great arteries].

PubMed

Alva-Espinosa, Carlos

2016-01-01

Corrected transposition of the great arteries is one of the most fascinating entities in congenital heart disease. The apparent corrected condition is only temporal. Over time, most patients develop systemic heart failure, even in the absence of associated lesions. With current imaging studies, precise visualization is achieved in each case though the treatment strategy remains unresolved. In asymptomatic patients or cases without associated lesions, focalized follow-up to assess systemic ventricular function and the degree of tricuspid valve regurgitation is important. In cases with normal ventricular function and mild tricuspid failure, it seems unreasonable to intervene surgically. In patients with significant associated lesions, surgery is indicated. In the long term, the traditional approach may not help tricuspid regurgitation and systemic ventricular failure. Anatomical correction is the proposed alternative to ease the right ventricle overload and to restore the systemic left ventricular function. However, this is a prolonged operation and not without risks and long-term complications. In this review the clinical, diagnostic, and therapeutic aspects are overviewed in the light of the most significant and recent literature.

Pseudo-acute myocardial infarction due to transient apical ventricular dysfunction syndrome (Takotsubo syndrome).

PubMed

Maciel, Bruno Araújo; Cidrão, Alan Alves de Lima; Sousa, Italo Bruno Dos Santos; Ferreira, José Adailson da Silva; Messias Neto, Valdevino Pedro

2013-03-01

Takotsubo syndrome is characterized by predominantly medial-apical transient left ventricular dysfunction, which is typically triggered by physical or emotional stress. The present article reports the case of a 61-year-old female patient presenting with dizziness, excessive sweating, and sudden state of ill feeling following an episode involving intense emotional stress. The physical examination and electrocardiogram were normal upon admission, but the troponin I and creatine kinase-MB concentrations were increased. Acute myocardial infarction without ST segment elevation was suspected, and coronary angiography was immediately performed, which showed severe diffuse left ventricular hypokinesia, medial-apical systolic ballooning, and a lack of significant coronary injury. The patient was referred to the intensive care unit and was successfully treated with supportive therapy. As this case shows, Takotsubo syndrome might simulate the clinical manifestations of acute myocardial infarction, and coronary angiography is necessary to distinguish between both myocardial infarction and myocardial infarction in the acute stage. The present patient progressed with spontaneous resolution of the ventricular dysfunction without any sequelae.

Models of ventricular structure and function reviewed for clinical cardiologists.

PubMed

Lunkenheimer, Paul P; Niederer, Peter; Sanchez-Quintana, Damian; Murillo, Margarita; Smerup, Morten

2013-04-01

The architectural arrangement of cardiomyocytes aggregated together within the ventricular walls remains controversial. Two models currently attract clinical attention, with neither model standing rigorous anatomical scrutiny. The first is based on the notion that ventricular mass can be unraveled consistently to produce a unique myocardial band. The second model was initially based on the notion that cardiomyocytes were bundled together in uniform fashion, with fibrous shelves interposed in transmural fashion. This concept was subsequently modified to accept the fact that the fibrous matrix supporting the cardiomyocytes within the ventricular walls does not form transmural sheets. Current observations demonstrate that not all cardiomyocytes are aggregated together in tangential fashion. A significant netting component is aligned in obliquely intruding and transversal fashion. The interaction between the tangential and transversal chains of cardiomyocytes with the fibrous matrix produces antagonistic forces, with both unloading and auxotonic forces necessary to explain normal and abnormal cardiodynamics. This article is part of a JCTR special issue on Cardiac Anatomy.

Pseudo-acute myocardial infarction due to transient apical ventricular dysfunction syndrome (Takotsubo syndrome)

PubMed Central

Maciel, Bruno Araújo; Cidrão, Alan Alves de Lima; Sousa, Ítalo Bruno dos Santos; Ferreira, José Adailson da Silva; Messias Neto, Valdevino Pedro

2013-01-01

Takotsubo syndrome is characterized by predominantly medial-apical transient left ventricular dysfunction, which is typically triggered by physical or emotional stress. The present article reports the case of a 61-year-old female patient presenting with dizziness, excessive sweating, and sudden state of ill feeling following an episode involving intense emotional stress. The physical examination and electrocardiogram were normal upon admission, but the troponin I and creatine kinase-MB concentrations were increased. Acute myocardial infarction without ST segment elevation was suspected, and coronary angiography was immediately performed, which showed severe diffuse left ventricular hypokinesia, medial-apical systolic ballooning, and a lack of significant coronary injury. The patient was referred to the intensive care unit and was successfully treated with supportive therapy. As this case shows, Takotsubo syndrome might simulate the clinical manifestations of acute myocardial infarction, and coronary angiography is necessary to distinguish between both myocardial infarction and myocardial infarction in the acute stage. The present patient progressed with spontaneous resolution of the ventricular dysfunction without any sequelae. PMID:23887762

Atrial fibrillation management in a breeding stallion.

PubMed

Heliczer, N; Mitchell, K; Lorello, O; Dauvillier, J; Burger, D; Schwarzwald, C C; Navas de Solis, C

2017-06-01

A 20-year-old warmblood breeding stallion presented to a University practice for semen collection and evaluation was incidentally diagnosed with atrial fibrillation (AF). Electrocardiogram recordings during breeding revealed inappropriately rapid tachycardia and occasional ventricular premature depolarizations/aberrant ventricular conduction. Transvenous electrical cardioversion was performed. After successful cardioversion the horse displayed supraventricular ectopy and atrial contractile dysfunction and was administered sotalol hydrochloride in an attempt to decrease the risk of AF recurrence. Supraventricular ectopy and echocardiographic evidence of atrial dysfunction gradually improved and normalized over 6 months. No direct adverse effects of the chronic anti-arrhythmic treatment were observed and libido and semen quality were unaffected. AF recurred 6 months after cardioversion and sotalol therapy was continued to control the ventricular ectopy/aberrant ventricular conduction during semen collection. Considerations regarding pathologic arrhythmias and inappropriately high heart rates in breeding stallions with AF may be similar to those in riding horses. Sotalol hydrochloride was a safe anti-arrhythmic drug in the management of this case. Copyright © 2017 Elsevier B.V. All rights reserved.

[The importance of bisoprolol in prevention of heart left ventricular hypertrophy in patients with long term L-thyroxin suppressive therapy, after the operation of differentiated thyroid carcinoma].

PubMed

Matuszewska, Gabriela; Marek, Bogdan; Kajdaniuk, Dariusz; Przywara-Chowaniec, Brygida; Jarzab, Jerzy; Jarzab, Barbara

2007-01-01

Patients with differentiated thyroid carcinoma have to undergo radical surgical treatment, which includes total thyreoidectomy, radioiodine therapy and a life-time suppressive therapy with L-thyroxine. The aim of this study was a prospective evaluation of left ventricular hypertrophy during L suppressive-thyroxine treatment in patients treated for differentiated thyroid carcinoma. The examined group comprised 50 patients with differentiated thyroid carcinoma, treated by total thyroidectomy and 131I therapy. Echocardiographic measurements were needed for estimation of left ventricular mass and its index, according to recommendations of American Echocardiography Society. During two-years long suppressive therapy we observed a significant rise in left ventricular mass. In woman group left ventricular mass was increased from 168+/-39 g to 204+/-45 g (p<0.001) and in men from 205+/-60 to 320+/-21 g. Likewise, left ventricular mass index was increased in women group from 96+/-18 g/m(2) to 116+/-25 g/m(2) (p<0.001) and in men group from 107+/-37 g/m(2) to 158+/-28 g/m(2). Simultaneous treatment with bisoprolol caused a regression of left myocardial hypertrophy. Already after 6 months of simultaneous treatment with L-thyroxin and bisoprolol, for left ventricular mass was reduced to normal: in woman 165+/-35 g, and in men to 178+/-38 g. Analogous results were obtained left ventricular mass index. After 6 months it was reduced to 94+/-12 g/m(2) in woman and in men to 132+/-32 g/m(2). 1. In differentiated thyroid cancer patients, treated postoperatively with L-thyroxine suppressive therapy, left ventricular hypertrophy is observed already during the first year of suppressive therapy and progresses during the next year of treatment. 2 Addition of a beta-adrenergic antagonist to suppressive doses of L-thyroxine causes a regression of left ventricular hypertrophy, thus, beta-adrenergic antagonists should be administered in this group of patients.

Mitral valve prolapse and electrolyte abnormality: a dangerous combination for ventricular arrhythmias

PubMed Central

Rajani, Ali Raza; Murugesan, Vagishwari; Baslaib, Fahad Omar; Rafiq, Muhammad Anwer

2014-01-01

A 27-year-old woman with a history of bileaflet mitral valve prolapse and moderate mitral regurgitation presented to our emergency with untractable polymorphic wide complex tachycardia and unstable haemodynamics. After cardiopulmonary resuscitation, return of spontaneous circulation was achieved 30 min later. Her post-resuscitation ECG showed a prolonged QT interval which progressively normalised over the same day. Her laboratory investigations revealed hypocalcaemia while other electrolytes were within normal limits. A diagnosis of ventricular arrhythmia secondary to structural heart disease further precipitated by hypocalcaemia was made. Further hospital stay did not reveal a recurrence of prolonged QT interval or other arrhythmias except for an episode of non-sustained ventricular tachycardia. However, the patient suffered diffuse hypoxic brain encephalopathy secondary to prolonged cardiopulmonary resuscitation. PMID:24827670

Accuracy and Reproducibility of Strain by Speckle Tracking in Pediatric Subjects with Normal Heart and Single Ventricular Physiology: A 2D Speckle Tracking Echocardiography and Magnetic Resonance Imaging Correlative Study

PubMed Central

Singh, Gautam K.; Cupps, Brian; Pasque, Michael; Woodard, Pamela K.; Holland, Mark R.; Ludomirsky, Achiau

2013-01-01

Background Myocardial strain is a sensitive measure of ventricular systolic function. Two-dimensional speckle-tracking echocardiography (2DSE) is an angle-independent method for strain measurement but has not been validated in pediatric subjects. We evaluated the accuracy and reproducibility of 2DSE-measured strain against reference tagged MRI-measured strain in pediatric subjects with normal hearts and those with single ventricle (SV) of left ventricle (LV) morphology s/p Fontan procedure. Methods Peak systolic circumferential (CS) and longitudinal (LS) strains in segments (n = 16) of LVs in age and BSA matched 20 healthy and 12 pediatric subjects with tricuspid atresia s/p Fontan procedure were measured by 2DSE and tagged MRI. Average (global) and regional segmental strains measured by two methods were compared using Spearman and Bland-Altman analyses. Results 2DSE and tagged MRI measured global strains demonstrated close agreements, which were better for LS than CS and in normal LVs than in SVs (95% limits of agreement: +0.0% to +3.12%, −2.48 % to +1.08%, −4.6% to +1.8% and −3.6% to +1.8% respectively). There was variability in agreement between regional strains with wider limits in apical than in basal regions in normal LVs and heterogeneous in SVs. The strain values were significantly (p < 0.05) higher in normal LVs than in SVs except for basal LSs, which were similar in both cohorts. The regional strains in normal LVs demonstrated an apico-basal magnitude gradient whereas SVs showed heterogeneity. The reproducibility was the most robust for images obtained with frame rates between 60 and 90 frame/sec; global LS in both cohorts; and basal strains in normal LVs. Conclusions 2DSE-measured strains agree with MRI-measured strain globally but vary regionally particularly in SVs. Global strain may be more robust tool for the cardiac function evaluation than regional strain in SV physiology. The reliability of 2DSE measured strain is affected by the frame rate, nature of strain, and ventricular geometry. PMID:20850945

Cardiac support device (ASD) delivers bone marrow stem cells repetitively to epicardium has promising curative effects in advanced heart failure.

PubMed

Yue, Shizhong; Naveed, Muhammad; Gang, Wang; Chen, Dingding; Wang, Zhijie; Yu, Feng; Zhou, Xiaohui

2018-05-12

Ventricular restraint therapy is a non-transplant surgical option for the management of advanced heart failure (HF). To augment the therapeutic applications, it is hypothesized that ASD shows remarkable capabilities not only in delivering stem cells but also in dilated ventricles. Male SD rats were divided into four groups (n = 6): normal, HF, HF + ASD, and HF + ASD-BMSCs respectively. HF was developed by left anterior descending (LAD) coronary artery ligation in all groups except normal group. Post-infarcted electrocardiography (ECG) and brain natriuretic peptide (BNP) showed abnormal heart function in all model groups and HF + ASD-BMSCs group showed significant improvement as compared to other HF, HF + ASD groups on day 30. Masson's trichrome staining was used to study the histology, and a large blue fibrotic area has been observed in HF and HF + ASD groups and quantification of fibrosis was assessed. ASD-treated rats showed normal heart rhythm, demonstrated by smooth -ST and asymmetrical T-wave. The mechanical function of the heart such as left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and heart rate was brought to normal when treated with ASD-BMSCs. This effect was more prominent than that of ASD therapy alone. In comparison to HF group, the SD rats in HF + ASD-BMBCs group showed a significant decline in BNP levels. So ASD can deliver BMSCs to the cardiomyocytes successfully and broaden the therapeutic efficacy, in comparison to the restraint device alone. An effective methodology to manage the end-stage HF has been proved.

Microdose computed tomographic cardiac angiography in normal cats.

PubMed

Rodriguez, Kiira T; O'Brien, Mauria A; Hartman, Susan K; Mulherin, Allison C; McReynolds, Casie J; McMichael, Maureen; Rapoport, Gregg; O'Brien, Robert T

2014-03-01

To determine if microdose contrast-enhanced multi-detector computed tomographic angiography (MDCTA) allows characterization of cardiac chambers in lightly sedated normal cats. Seven healthy domestic cats. Lightly sedated normal cats were imaged pre-contrast and with microdose (0.22 ml/kg of non-ionic iodinated contrast medium, 300 mg I/ml) triple-phase MDCTA in a motion restriction device. On pre-contrast images, the aorta (median: 52.43 Hounsfield units [HU], range 27.35-76.74 HU) was outlined by significantly (p = 0.015) lower attenuating periaortic fat (-66.16 HU, -42.62 to -92.77 HU). On post-contrast images, median peak contrast enhancement in the right ventricle (111.77 HU, 36.09-141.60 HU) was achieved in 3.1 s (range 2.9-7.3 s), in the aorta (149.30 HU, 99.43-319.60 HU) and left atrium (180.83 HU, 88.53-266.84 HU) in 6.4 s (range 5.6-7.7 s) and in the left ventricle (147.89 HU, 57.23-245.77 HU) in 7.10 s (range 6.2-11.2 s). Significantly higher attenuation was measured between all chambers and walls, the right ventricular lumen and interventricular septum (median ratio 53.78 HU, range 0.21-83.20 HU), left ventricular lumen and left ventricular free wall (89.32 HU, 38.81-185.95 HU) and aorta and periaortic fat (190.43 HU, 143.22-425.44 HU) on post-contrast images. Sufficient biological contrast is available on survey CT to discriminate between the aorta and the left atrium, and microdose MDCTA provides sufficient contrast enhancement for adequate visualization of the heart chambers in normal cats. Copyright © 2014 Elsevier B.V. All rights reserved.

Cardiac memory in patients with Wolff-Parkinson-White syndrome: noninvasive imaging of activation and repolarization before and after catheter ablation.

PubMed

Ghosh, Subham; Rhee, Edward K; Avari, Jennifer N; Woodard, Pamela K; Rudy, Yoram

2008-08-26

Cardiac memory refers to a change in ventricular repolarization induced by and persisting for minutes to months after cessation of a period of altered ventricular activation (eg, resulting from pacing or preexcitation in patients with Wolff-Parkinson-White syndrome). ECG imaging (ECGI) is a novel imaging modality for noninvasive electroanatomic mapping of epicardial activation and repolarization. Fourteen pediatric patients with Wolff-Parkinson-White syndrome and no other congenital disease, were imaged with ECGI a day before and 45 minutes, 1 week, and 1 month after successful catheter ablation. ECGI determined that preexcitation sites were consistent with sites of successful ablation in all cases to within a 1-hour arc of each atrioventricular annulus. In the preexcited rhythm, activation-recovery interval (ARI) was the longest (349+/-6 ms) in the area of preexcitation leading to high average base-to-apex ARI dispersion of 95+/-9 ms (normal is approximately 40 ms). The ARI dispersion remained the same 45 minutes after ablation, although the activation sequence was restored to normal. ARI dispersion was still high (79+/-9 ms) 1 week later and returned to normal (45+/-6 ms) 1 month after ablation. The study demonstrates that ECGI can noninvasively localize ventricular insertion sites of accessory pathways to guide ablation and evaluate its outcome in pediatric patients with Wolff-Parkinson-White syndrome. Wolff-Parkinson-White is associated with high ARI dispersion in the preexcited rhythm that persists after ablation and gradually returns to normal over a period of 1 month, demonstrating the presence of cardiac memory. The 1-month time course is consistent with transcriptional reprogramming and remodeling of ion channels.

Detrimental effect of hypothermia during acute normovolaemic haemodilution in anaesthetized cats

NASA Astrophysics Data System (ADS)

Talwar, A.; Fahim, Mohammad

Haemodynamic responses to hypothermia were studied at normal haematocrit and following the induction of acute normovolaemic haemodilution. Experiments were performed on 20 cats anaesthetized with a mixture of chloralose and urethane in two groups. In one group (n=10) the effects of hypothermia on various haemodynamic variables were studied at normal haematocrit (41.0+/-1.7%) and in the second group of cats (n=10) the effects of hypothermia on various haemodynamic variables were studied after the induction of acute normovolaemic haemodilution (14.0+/-1.0%). The haemodynamic variables left ventricular pressure, left ventricular contractility, arterial blood pressure, heart rate and right atrial pressure were recorded on a polygraph. Cardiac output was measured using a cardiac output computer. In both groups hypothermia was induced by surface cooling with the help of ice. Cardiovascular variables were recorded at each 1° C fall in body temperature. Hypothermia produced a significant (P<0.05) drop in heart rate, cardiac output, arterial blood pressure and left ventricular contractility in both groups. However, the percentage decrease in these variables in response to hypothermia was significantly (P<0.05) higher in cats with low haematocrit than in those with normal haematocrit. The severity of hypothermia - induced cardiovascular effects is evident from the drastic decrease in heart rate, cardiac output, arterial blood pressure and myocardial contractility in cats with low haematocrit, indicating a higher risk of circulatory failure under anaemic conditions at low temperatures.

Analysis of Morphological Characteristics and Origins of Idiopathic Premature Ventricular Contractions Under a 12-Lead Electrocardiogram in Children with Structurally Normal Hearts.

PubMed

Jiang, Jianbin; He, Yuee; Qiu, Huixian; Zhang, Yuanhai; Chu, Maoping; Li, Yuechun; Chen, Qi

2017-10-21

Up to 40% of healthy children have premature ventricular complexes or contractions (PVCs) detected with 24-hour Holter monitoring. We aimed to investigate the morphological characteristics and origins of idiopathic PVCs under a 12-lead electrocardiogram in children with structurally normal hearts. All asymptomatic monomorphic PVC patients with structurally normal hearts under 18 years of age were included in this retrospective study. Characteristics of PVCs in lead V 1 under a 12-lead electrocardiogram were classified as left bundle branch block (PVC-LBBB) or right bundle branch block (PVC-RBBB). According to limb leads, PVC-LBBB or PVC-RBBB was divided into: PVCs-LBBB type I; PVCs-LBBB type II; PVCs-RBBB type I; PVCs-RBBB type II; and PVCs-RBBB type III. Out of 178 PVC patients, 94 cases of PVCs-LBBB (PVCs-LBBB type I = 60; PVCs-LBBB type II = 34) and 84 cases of PVCs-RBBB (PVCs-RBBB type I = 3; PVCs-RBBB type II = 55; PVCs-RBBB type III = 26) were identified. The frequency of PVCs-LBBB type I increased with age and the frequency of PVCs-RBBB type II and III decreased with age. Among the children monitor tested, from 1 years old to 18 years old, PVCs originating from the left or right ventricular outflow tract gradually increased with age, while PVCs originating from the branch sources decreased with age.

Beat-to-Beat Variability of Ventricular Action Potential Duration Oscillates at Low Frequency During Sympathetic Provocation in Humans

PubMed Central

Porter, Bradley; van Duijvenboden, Stefan; Bishop, Martin J.; Orini, Michele; Claridge, Simon; Gould, Justin; Sieniewicz, Benjamin J.; Sidhu, Baldeep; Razavi, Reza; Rinaldi, Christopher A.; Gill, Jaswinder S.; Taggart, Peter

2018-01-01

Background: The temporal pattern of ventricular repolarization is of critical importance in arrhythmogenesis. Enhanced beat-to-beat variability (BBV) of ventricular action potential duration (APD) is pro-arrhythmic and is increased during sympathetic provocation. Since sympathetic nerve activity characteristically exhibits burst patterning in the low frequency range, we hypothesized that physiologically enhanced sympathetic activity may not only increase BBV of left ventricular APD but also impose a low frequency oscillation which further increases repolarization instability in humans. Methods and Results: Heart failure patients with cardiac resynchronization therapy defibrillator devices (n = 11) had activation recovery intervals (ARI, surrogate for APD) recorded from left ventricular epicardial electrodes alongside simultaneous non-invasive blood pressure and respiratory recordings. Fixed cycle length was achieved by right ventricular pacing. Recordings took place during resting conditions and following an autonomic stimulus (Valsalva). The variability of ARI and the normalized variability of ARI showed significant increases post Valsalva when compared to control (p = 0.019 and p = 0.032, respectively). The oscillatory behavior was quantified by spectral analysis. Significant increases in low frequency (LF) power (p = 0.002) and normalized LF power (p = 0.019) of ARI were seen following Valsalva. The Valsalva did not induce changes in conduction variability nor the LF oscillatory behavior of conduction. However, increases in the LF power of ARI were accompanied by increases in the LF power of systolic blood pressure (SBP) and the rate of systolic pressure increase (dP/dtmax). Positive correlations were found between LF-SBP and LF-dP/dtmax (rs = 0.933, p < 0.001), LF-ARI and LF-SBP (rs = 0.681, p = 0.001) and between LF-ARI and LF-dP/dtmax (rs = 0.623, p = 0.004). There was a strong positive correlation between the variability of ARI and LF power of ARI (rs = 0.679, p < 0.001). Conclusions: In heart failure patients, physiological sympathetic provocation induced low frequency oscillation (~0.1 Hz) of left ventricular APD with a strong positive correlation between the LF power of APD and the BBV of APD. These findings may be of importance in mechanisms underlying stability/instability of repolarization and arrhythmogenesis in humans. PMID:29670531

Cardiac function, myocardial mechano-energetic efficiency, and ventricular-arterial coupling in normal pregnancy.

PubMed

Iacobaeus, Charlotte; Andolf, Ellika; Thorsell, Malin; Bremme, Katarina; Östlund, Eva; Kahan, Thomas

2018-04-01

To assess cardiac function, myocardial mechanoenergetic efficiency (MEE), and ventricular-arterial coupling (VAC) longitudinally during normal pregnancy, and to study if there was an association between cardiac structure and function, and fetal growth. Cardiac structure and function, MEE, and ventricular-arterial coupling was assessed longitudinally in 52 healthy nulliparous women at 14, 24, and 34 weeks' gestation and 9-month postpartum. Left atrial diameter increased during pregnancy (30.41 ± 3.59 mm in the nonpregnant state and 31.02 ± 3.91, 34.06 ± 3.58, and 33.9 ± 2.97 mm in the first, second, and third trimesters, P < 0.001). Left ventricular mass increased 117.12 ± 45.0 g in the nonpregnant state and 116.5 ± 33.0, 126.9 ± 34.5, 128.4 ± 36 g in the first, second, and third trimesters (P < 0.001). Cardiac output increased from 3.4 ± 1.2 l/min to 4.3 ± 0.7 l/min in the second and third trimesters (P < 0.001). Diastolic function decreased as both E/A and e'/a' decreased during pregnancy (P < 0.05 and P < 0.001, respectively). MEE and VAC were retained during pregnancy. Heart rate was associated with birth weight centile in the first (r = 0.41, P = 0.002) and second (r = 0.46, P = 0.002) trimester. The increase in cardiac output during normal pregnancy is obtained by an increase in heart rate, followed by structural cardiac changes. The impaired systolic function is accomplished by a deteriorated diastolic function. Despite these rapid changes, the myocardium manages to work efficient with a preserved MEE. Cardiac and arterial adaption to pregnancy seems to appear parallel as evidenced by a preserved VAC.

Systolic anterior motion of the mitral valve associated with right ventricular systolic hypertension in 9 dogs.

PubMed

Paige, Christopher F; Abbott, Jonathan A; Pyle, R Lee

2007-05-01

To describe the zoographic and echocardiographic characteristics of canine patients in which systolic anterior motion of the mitral valve (SAM) was identified in association with right ventricular systolic hypertension (RVSH). Medical records and digitally recorded echocardiographic examinations were reviewed for RVSH and two-dimensional (2DE) or M-mode echocardiographic evidence of SAM. SAM was identified in association with RSVH in 9 patients; 5 had pulmonic stenosis, 2 had tetralogy of Fallot and 2, pulmonary hypertension. Relative to body weight, the end-diastolic and end-systolic left ventricular dimensions were subnormal in all patients. Hyperdynamic left ventricular systolic performance was identified in 8 of 9 patients. In 5 of the 9 patients, SAM was mild or moderate in degree. Left ventricular outflow tract (LVOT) obstruction and mitral valve regurgitation were documented by Doppler studies in only 3 of the 4 patients with marked SAM. However, late systolic acceleration within the LVOT was recorded in 2 additional patients for whom peak velocities were normal. In the cases described here, the presence of SAM is likely explained by alterations in left ventricular geometry and function associated with diminished pulmonary venous return together with sympathetic activation resulting from subnormal stroke volume. Although the hemodynamic consequences were apparently minor, the association of SAM with right-sided heart disease might be of interest to those engaged in the practice of veterinary echocardiography.

Vulnerability to ventricular fibrillation

NASA Astrophysics Data System (ADS)

Janse, Michiel J.

1998-03-01

One of the factors that favors the development of ventricular fibrillation is an increase in the dispersion of refractoriness. Experiments will be described in which an increase in dispersion in the recovery of excitability was determined during brief episodes of enhanced sympathetic nerve activity, known to increase the risk of fibrillation. Whereas in the normal heart ventricular fibrillation can be induced by a strong electrical shock, a premature stimulus of moderate intensity only induces fibrillation in the presence of regional ischemia, which greatly increases the dispersion of refractoriness. One factor that is of importance for the transition of reentrant ventricular tachycardia to ventricular fibrillation during acute regional ischemia is the subendocardial Purkinje system. After selective destruction of the Purkinje network by lugol, reentrant tachycardias still develop in the ischemic region, but they do not degenerate into fibrillation. Finally, attempts were made to determine the minimal mass of thin ventricular myocardium required to sustain fibrillation induced by burst pacing. This was done by freezing of subendocardial and midmural layers. The rim of surviving epicardial muscle had to be larger than 20 g. Extracellular electrograms during fibrillation in both the intact and the "frozen" left ventricle were indistinguishable, but activation patterns were markedly different. In the intact ventricle epicardial activation was compatible with multiple wavelet reentry, in the "frozen" heart a single, or at most two wandering reentrant waves were seen.

Influence of microalbuminuria on left ventricular geometry and function in hypertensive patients with type 2 diabetes mellitus.

PubMed

Picca, Maurizio; Agozzino, Francesco; Pelosi, Giancarlo

2003-01-01

An increased urinary albumin excretion (UAE) is associated with an augmented risk of cardiovascular disease in diabetic patients and in non-diabetic subjects. Left ventricular hypertrophy has been demonstrated to be a powerful predictor of cardiovascular morbidity and mortality in arterial hypertension and when the ventricular geometry is concentric the relation is even stronger. This echocardiographic and Doppler study was designed to evaluate the influence of microalbuminuria on the left ventricular geometry and function in hypertensive patients with type 2 diabetes melitus. Forty-two patients (16 males, 26 females, mean age 59.6 +/- 6.7 years) with mild-to-moderate essential hypertension and type 2 diabetes mellitus were enrolled in the study. Twenty-one patients had an elevated UAE (group 1) and 21 a normal UAE (group 2). M-mode (under two-dimensional control) and Doppler echocardiography were performed after a 4-week washout period off antihypertensive therapy. The left ventricular mass index was found to be greater than the partition value of 51 g/m2.7 in both groups but was significantly higher (p < 0.001) in group 1. The midwall fractional shortening was significantly lower (p < 0.001) in group 1 in comparison with group 2. The E/A ratio was impaired in both groups but was more significantly reduced (p < 0.02) in group 1. There was a significantly higher prevalence of a left ventricular concentric hypertrophy pattern (19/21 patients, p < 0.001) in group 1. In hypertensive patients with type 2 diabetes mellitus, an elevated UAE is associated with an increased left ventricular mass index, a higher prevalence of a concentric left ventricular hypertrophy pattern, a depressed midwall systolic performance and a markedly impaired diastolic function...

Renal sympathetic denervation modulates ventricular electrophysiology and has a protective effect on ischaemia-induced ventricular arrhythmia.

PubMed

Huang, Bing; Yu, Lilei; He, Bo; Lu, Zhibing; Wang, Songyun; He, Wenbo; Yang, Kang; Liao, Kai; Zhang, Ling; Jiang, Hong

2014-11-01

Recently, a beneficial effect of renal sympathetic denervation (RSD) has been seen in patients with ventricular electrical storm. However, the effect of RSD on ventricular electrophysiology remains unclear. Thirty-three mongrel dogs were included in the present study. Renal sympathetic denervation was performed by radiofrequency ablation of the adventitial surface of the renal artery. In group 1 (n = 8), programmed stimulation was performed before and after RSD to determine the ventricular effective refractory period (ERP) and action potential duration (APD) restitution properties. The same parameters were measured in five other animals that underwent sham RSD to serve as controls. In group 2 (n = 10), acute myocardial ischaemia (AMI) was induced by ligating the proximal left anterior descending coronary artery after the performance of RSD, and the incidence of ventricular arrhythmia (VA) was calculated during 1 h of recording. In another 10 dogs (group 3), AMI was induced and VA was measured with sham RSD. In group 1, RSD significantly prolonged ventricular ERP and APD, reduced the maximal slope (Smax) of the restitution curve and suppressed APD alternans at each site. Renal sympathetic denervation also significantly decreased the spatial dispersion of ERP, APD and Smax. In the five control animals, no significant electrophysiological change was detected after sham RSD. The occurrence of spontaneous VA during 1 h of AMI in group 2 was significantly lower than that in group 3. These data suggest that RSD stabilizes ventricular electrophysiological properties in normal hearts and reduces the occurrence of VA in hearts experiencing AMI. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

High Serum Phosphorus Level Is Associated with Left Ventricular Diastolic Dysfunction in Peritoneal Dialysis Patients.

PubMed

Ye, Min; Tian, Na; Liu, Yanqiu; Li, Wei; Lin, Hong; Fan, Rui; Li, Cuiling; Liu, Donghong; Yao, Fengjuan

We initiated this study to explore the relationships of serum phosphorus level with left ventricular ultrasound features and diastolic function in peritoneal dialysis (PD) patients. 174 patients with end-stage renal disease (ESRD) receiving PD were enrolled in this retrospective observational study. Conventional echocardiography examination and tissue Doppler imaging (TDI) were performed in each patient. Clinical information and laboratory data were also collected. Analyses of echocardiographic features were performed according to phosphorus quartiles groups. And multivariate regression models were used to determine the association between serum phosphorus and Left ventricular diastolic dysfunction (LVDD). With the increase of serum phosphorus levels, patients on PD showed an increased tissue Doppler-derived E/e' ratio of lateral wall (P < 0.001), indicating a deterioration of left ventricular diastolic function. Steady growths of left atrium and left ventricular diameters as well as increase of left ventricular muscle mass were also observed across the increasing quartiles of phosphorus, while left ventricular ejection fraction remained normal. In a multivariate analysis, the regression coefficient for E/e' ratio in the highest phosphorus quartile was almost threefold higher relative to those in the lowest quartile group. And compared with patients in the lowest phosphorus quartile (<1.34 mmol/L) those in the highest phosphorus quartile (>1.95 mmol/L) had a more than fivefold increased odds of E/e' ratio >15. Our study showed an early impairment of left ventricular diastolic function in peritoneal dialysis patients. High serum phosphorus level was independently associated with greater risk of LVDD in these patients. Whether serum phosphorus will be a useful target for prevention or improvement of LVDD remains to be proved by further studies.

Eccentric LVH healing after starting renal replacement therapy.

PubMed

Vertolli, Ugo; Lupia, Mario; Naso, Agostino

2002-01-01

Hypertension and left ventricular hypertrophy (LVH) are commonly associated in patients with CRF starting RDT. We report a case of eccentric LVH with marked dilatation and subsequent mitral incompetence of +3/4 that disappeared after three months of standard hemodialysis. Mrs SN, 62 years old, starting HD, had an echocardiography because of dyspnoea; the echo showed: dilated left atrium (78 ml/m2), moderately dilated left ventricle with normal systolic function (TDV 81 ml/m2, EF 66%), an increased ventricular mass (120 gr/m2) and a high grade mitral incompetence +3/4. After three months standard RDT and a dry weight only 2 kg less, the patients was normotensive without therapy, a cardiac angiogram with a hemodynamic study was performed as a pre-transplant workout: a normal left ventricle was found with normal systolic function (TDV 66, TSV 17, GS 49, EF 75%), and a perfectly competent mitral valve (reflux disappeared). The coronary angiography did not reveal critical stenosis. A new echocardiography confinned the data of the hemodynamic study: hypertensive cardiomiopathy with normal systolic function. After one year the patient has been transplanted, with a good renal function and the cardiac echo unchanged. Relieving uremic toxicity ameliorated the cardiac performance in this particular patient.

Phosphorylated tau/amyloid beta 1-42 ratio in ventricular cerebrospinal fluid reflects outcome in idiopathic normal pressure hydrocephalus

PubMed Central

2012-01-01

Background Idiopathic normal pressure hydrocephalus (iNPH) is a potentially reversible cause of dementia and gait disturbance that is typically treated by operative placement of a ventriculoperitoneal shunt. The outcome from shunting is variable, and some evidence suggests that the presence of comorbid Alzheimer's disease (AD) may impact shunt outcome. Evidence also suggests that AD biomarkers in cerebrospinal fluid (CSF) may predict the presence of AD. The aim of this study was to investigate the relationship between the phosphorylated tau/amyloid beta 1-42 (ptau/Aβ1-42) ratio in ventricular CSF and shunt outcome in patients with iNPH. Methods We conducted a prospective trial with a cohort of 39 patients with suspected iNPH. Patients were clinically and psychometrically assessed prior to and approximately 4 months after ventriculoperitoneal shunting. Lumbar and ventricular CSF obtained intraoperatively, and tissue from intraoperative cortical biopsies were analyzed for AD biomarkers. Outcome measures included performance on clinical symptom scales, supplementary gait measures, and standard psychometric tests. We investigated relationships between the ptau/Aβ1-42 ratio in ventricular CSF and cortical AD pathology, initial clinical features, shunt outcome, and lumbar CSF ptau/Aβ1-42 ratios in the patients in our cohort. Results We found that high ptau/Aβ1-42 ratios in ventricular CSF correlated with the presence of cortical AD pathology. At baseline, iNPH patients with ratio values most suggestive of AD presented with better gait performance but poorer cognitive performance. Patients with high ptau/Aβ1-42 ratios also showed a less robust response to shunting on both gait and cognitive measures. Finally, in a subset of 18 patients who also underwent lumbar puncture, ventricular CSF ratios were significantly correlated with lumbar CSF ratios. Conclusions Levels of AD biomarkers in CSF correlate with the presence of cortical AD pathology and predict aspects of clinical presentation in iNPH. Moreover, preliminary evidence suggests that CSF biomarkers of AD may prove useful for stratifying shunt prognosis in patients being evaluated and treated for this condition. PMID:22444461

[Value of a novel categorization of congenital double-outlet right ventricle on guiding the choice of surgical approaches].

PubMed

Pang, Kunjing; Meng, Hong; Wang, Hao; Hu, Shengshou; Hua, Zhongdong; Pan, Xiangbin; Li, Shoujun

2015-11-01

To explore the feasibility and value of a new categorization of double outlet right ventricular (DORV) on guiding the optimal choices of surgical approaches. Five hundred and twenty one DORV patients diagnosed by echocardiography, angiocardiography and CT at Fuwai Hospital from May 2003 to September 2014 were enrolled in this retrospective study. Congenital DORV was categorized according to three basic factors as follows: the positional relationships of great arteries (normal relation or abnormal relation), the relationships of the ventricular septal defect (VSD) to the great arteries (committed VSD or remote VSD), the presence or absence of pulmonary outflow tract obstruction (POTO). Eight types of DORV were established: type I (normal relation, committed VSD, without POTO), type II (normal relation, committed VSD, POTO), type III (normal relation, remote VSD, without POTO), type IV (normal relation, remote VSD, POTO), type V (abnormal relation, committed VSD, without POTO), type VI (abnormal relation, committed VSD, POTO), type VII (abnormal relation, remote VSD, without POTO), type VIII (abnormal relation, remote VSD, POTO). Feasibility of this classification and the value of this classification on guiding the choice of surgical approaches were analyzed. Among the five hundred and twenty one patients, there were 90 patients (17.3%) with type I DORV, 94 patients (18.0%) with type II, 33 patients (6.3%) with type III, 34 patients (6.5%) with type IV, 64 patients (12.3%) with type V, 61 patients (11.7%) with type VI, 33 patients (6.3%) with type VII, 112 patients (21.5%) with type VIII. Thus, all patients could be typed by this classification method. The echocardiography diagnosis was consistent with the intra-operative and or cardiac catheterization/CT findings. Excluding the contraindications of bi-ventricular repair, different surgical approaches were performed in every subtype of DORV according the classification, which indicated that this novel categorization could accurately guide the clinic managements. This novel DORV categorization can accurately diagnose DORV lesions, and guide the clinic therapy choice.

A modified Glenn shunt reduces venous congestion during acute right ventricular failure due to pulmonary banding: a randomized experimental study

PubMed Central

Vikholm, Per; Schiller, Petter; Hellgren, Laila

2014-01-01

OBJECTIVES Right ventricular failure after left ventricular assist device implantation is a serious complication with high rates of mortality and morbidity. It has been demonstrated in experimental settings that volume exclusion of the right ventricle with a modified Glenn shunt can improve haemodynamics during ischaemic right ventricular failure. However, the concept of a modified Glenn shunt is dependent on a normal pulmonary vascular resistance, which can limit its use in some patients. The aim of this study was to explore the effects of volume exclusion with a modified Glenn shunt during right ventricular failure due to pulmonary banding, and to study the alterations in genetic expression in the right ventricle due to pressure and volume overload. METHODS Experimental right ventricular failure was induced in pigs (n = 11) through 2 h of pulmonary banding. The pigs were randomized to either treatment with a modified Glenn shunt and pulmonary banding (n = 6) or solely pulmonary banding (n = 5) as a control group. Haemodynamic measurements, blood samples and right ventricular biopsies for genetic analysis were sampled at baseline, at right ventricular failure (i.e. 2 h of pulmonary banding) and 1 h post-right ventricular failure in both groups. RESULTS Right atrial pressure increased from 10 mmHg (9.0–12) to 18 mmHg (16–22) (P < 0.01) and the right ventricular pressure from 31 mmHg (26–35) to 57 mmHg (49–61) (P < 0.01) after pulmonary banding. Subsequent treatment with the modified Glenn shunt resulted in a decrease in right atrial pressure to 13 mmHg (11–14) (P = 0.03). In the control group, right atrial pressure was unchanged at 19 mmHg (16–20) (P = 0.18). At right heart failure, there was an up-regulation of genes associated with heart failure, inflammation, angiogenesis, negative regulation of cell death and proliferation. CONCLUSIONS Volume exclusion with a modified Glenn shunt during right ventricular failure reduced venous congestion compared with the control group. The state of right heart failure was verified through genetic expressional changes. PMID:24396048

Cerebrovascular accidents in patients with a ventricular assist device.

PubMed

Tsukui, Hiroyuki; Abla, Adib; Teuteberg, Jeffrey J; McNamara, Dennis M; Mathier, Michael A; Cadaret, Linda M; Kormos, Robert L

2007-07-01

A cerebrovascular accident is a devastating adverse event in a patient with a ventricular assist device. The goal was to clarify the risk factors for cerebrovascular accident. Prospectively collected data, including medical history, ventricular assist device type, white blood cell count, thrombelastogram, and infection, were reviewed retrospectively in 124 patients. Thirty-one patients (25%) had 48 cerebrovascular accidents. The mean ventricular assist device support period was 228 and 89 days in patients with and without cerebrovascular accidents, respectively (P < .0001). Sixty-six percent of cerebrovascular accidents occurred within 4 months after implantation. Actuarial freedom from cerebrovascular accident at 6 months was 75%, 64%, 63%, and 33% with the HeartMate device (Thoratec Corp, Pleasanton, Calif), Thoratec biventricular ventricular assist device (Thoratec Corp), Thoratec left ventricular assist device (Thoratec), and Novacor device (WorldHeart, Oakland, Calif), respectively. Twenty cerebrovascular accidents (42%) occurred in patients with infections. The mean white blood cell count at the cerebrovascular accident was greater than the normal range in patients with infection (12,900/mm3) and without infection (9500/mm3). The mean maximum amplitude of the thrombelastogram in the presence of infection (63.6 mm) was higher than that in the absence of infection (60.7 mm) (P = .0309). The risk of cerebrovascular accident increases with a longer ventricular assist device support period. Infection may activate platelet function and predispose the patient to a cerebrovascular accident. An elevation of the white blood cell count may also exacerbate the risk of cerebrovascular accident even in patients without infection. Selection of device type, prevention of infection, and meticulous control of anticoagulation are key to preventing cerebrovascular accident.

Correlations between ventricular enlargement and gray and white matter volumes of cortex, thalamus, striatum, and internal capsule in schizophrenia.

PubMed

Horga, Guillermo; Bernacer, Javier; Dusi, Nicola; Entis, Jonathan; Chu, Kingwai; Hazlett, Erin A; Haznedar, M Mehmet; Kemether, Eileen; Byne, William; Buchsbaum, Monte S

2011-10-01

Ventricular enlargement is one of the most consistent abnormal structural brain findings in schizophrenia and has been used to infer brain shrinkage. However, whether ventricular enlargement is related to local overlying cortex and/or adjacent subcortical structures or whether it is related to brain volume change globally has not been assessed. We systematically assessed interrelations of ventricular volumes with gray and white matter volumes of 40 Brodmann areas (BAs), the thalamus and its medial dorsal nucleus and pulvinar, the internal capsule, caudate and putamen. We acquired structural MRI ( patients with schizophrenia (n = 64) and healthy controls (n = 56)) and diffusion tensor fractional anisotropy (FA) (untreated schizophrenia n = 19, controls n = 32). Volumes were assessed by manual tracing of central structures and a semi-automated parcellation of BAs. Patients with schizophrenia had increased ventricular size associated with decreased cortical gray matter volumes widely across the brain; a similar but less pronounced pattern was seen in normal controls; local correlations (e.g. temporal horn with temporal lobe volume) were not appreciably higher than non-local correlations (e.g. temporal horn with prefrontal volume). White matter regions adjacent to the ventricles similarly did not reveal strong regional relationships. FA and center of mass of the anterior limb of the internal capsule also appeared differentially influenced by ventricular volume but findings were similarly not regional. Taken together, these findings indicate that ventricular enlargement is globally interrelated with gray matter volume diminution but not directly correlated with volume loss in the immediately adjacent caudate, putamen, or internal capsule.

Idiopathic accelerated idioventricular rhythm or ventricular tachycardia originating from the right bundle branch: unusual type of ventricular arrhythmia.

PubMed

Chen, Minglong; Gu, Kai; Yang, Bing; Chen, Hongwu; Ju, Weizhu; Zhang, Fengxiang; Yang, Gang; Li, Mingfang; Lu, Xinzheng; Cao, Kejiang; Ouyang, Feifan

2014-12-01

Accelerated idioventricular rhythm (AIVR) or ventricular tachycardia (VT) originating from the right bundle branch (RBB) is rare and published clinical data on such arrhythmia are scarce. In this study, we will describe the clinical manifestations, diagnosis, and management of a cohort of patients with this novel arrhythmia. Eight patients (5 men; median age, 25 years) with RBB-AIVR/VT were consecutively enrolled in the study. Pharmacological testing, exercise treadmill testing, electrophysiological study, and catheter ablation were performed in the study patients, and ECG features were characterized. All RBB-AIVR/VTs were of typical left bundle-branch block morphology with atrioventricular dissociation. The arrhythmias, which demonstrated chronotropic variability, were often isorhythmic with sinus rhythm and were accelerated by physical exercise, stress, and intravenous isoprenaline infusion. The rate of RBB-AIVR/VT varied from 45 to 200 beats per minute. Two patients experienced syncope, and 3 had impaired left ventricular function. Metoprolol was proven to be the most effective drug to decelerate the arrhythmia rate and relieve symptoms. Electrophysiology study was performed in 5 patients and the earliest activation with a sharp RBB potential was localized in the mid or distal RBB area. Catheter ablation terminated the arrhythmia with subsequent RBB block morphology during sinus rhythm. During follow-up, patients' symptoms were controlled with normalization of left ventricular function either on metoprolol or by catheter ablation. RBB-AIVR/VT is an unusual type of ventricular arrhythmia. It can result in significant symptoms and depressed ventricular function and can be successfully treated with catheter ablation. © 2014 American Heart Association, Inc.

Increased response of diastolic blood pressure to exercise in patients with coronary artery disease: an index of latent ventricular dysfunction?

PubMed Central

Paraskevaidis, I A; Kremastinos, D T; Kassimatis, A S; Karavolias, G K; Kordosis, G D; Kyriakides, Z S; Toutouzas, P K

1993-01-01

OBJECTIVE--To determine whether an abnormal response of diastolic blood pressure during treadmill exercise stress testing correlated with the number of obstructed vessels and with left ventricular systolic function in patients with coronary artery disease. DESIGN--Diastolic blood pressure was measured invasively during exercise stress testing and coronary angiograms and left ventriculograms were obtained at rest in patients with coronary artery disease. The abnormal (> or = 15 mm Hg) diastolic blood pressure response was compared with the number of obstructed coronary arteries and with left ventricular systolic function. SETTING--Two tertiary referral centres. PATIENTS--50 consecutive patients (mean age 57 years) with coronary artery disease. MAIN OUTCOME MEASURES--The increase in diastolic blood pressure during exercise and its correlation with the appearance and disappearance of ST segment deviation, resting left ventricular systolic function, and the number of obstructed coronary arteries. RESULTS--Group 1: 10 (20%) patients (three with one, four with two, and three with three vessel coronary artery disease) (mean (SD) age 54.7 (12) years) had an abnormal diastolic blood pressure response that appeared 1.2 (0.3) min before ST segment deviation and became normal 0.9 (0.3) min after the ST segment returned to normal. Group 2: 40 (80%) patients (12 with one, 16 with two, and 12 with three vessel coronary arteries disease) (aged 56.8 (8.2) years) had a normal diastolic blood pressure response to stress testing. The ejection fraction (46.3 (5)%) and cardiac index (2.6 (0.1) 1/min/m2) in group 1 were less than in group 2 (61.6 (4.2)% and 3.8 (0.3) 1/min/m2 respectively, p < or = 0.001). The end systolic volume was greater in group 1 than in group 2: 38.7 (0.7 ml/m2 v 28.2 (2.1) ml/m2, p < or = 0.001. CONCLUSION--In patients with coronary artery disease an abnormal increase in diastolic blood pressure during exercise stress testing correlated well with left ventricular systolic function at rest but not with the number of obstructed coronary arteries. The abnormal response of diastolic blood pressure probably reflects deterioration of myocardial function. Images PMID:8343317

Risk Stratification of Future Left Ventricular Dysfunction for Patients with Indications for Right Ventricular Pacing due to Bradycardia.

PubMed

Ooka, Junichi; Tanaka, Hidekazu; Hatani, Yutaka; Hatazawa, Keiko; Matsuzoe, Hiroki; Shimoura, Hiroyuki; Sano, Hiroyuki; Sawa, Takuma; Motoji, Yoshiki; Mochizuki, Yasuhide; Ryo-Koriyama, Keiko; Matsumoto, Kensuke; Fukuzawa, Koji; Hirata, Ken-Ichi

2017-10-21

Although right ventricular (RV) pacing is the only effective treatment for patients with symptomatic bradycardia, it creates left ventricular (LV) dyssynchrony, which can induce LV dysfunction and heart failure. The current criterion for consideration of cardiac resynchronization therapy (CRT) is LV ejection fraction (LVEF) ≤ 35%, but indication for CRT in patients required for RV pacing with LVEF > 35% remains unclear.We studied 40 patients, all LVEF ≥ 35%, who had undergone implantable cardioverter-defibrillator implantation with RV pacing < 5%. Echocardiography was performed at baseline and during RV pacing. LV dyssynchrony was defined as anteroseptal-to-posterior wall delay from the mid-LV short-axis view using two-dimensional speckle-tracking radial strain (significant: ≥ 130 ms). Patients were divided into two groups based on baseline LVEF: normal LVEF ( ≥ 50%; n = 20) and mildly reduced LVEF (35-50%; n = 20).LVEF and LV dyssynchrony in patients with mildly reduced LVEF deteriorated significantly during RV pacing compared to those in patients with normal LVEF. Moreover, changes in LV dyssynchrony during RV pacing significantly correlated with changes in LVEF (r = -0.44, P < 0.01). Multivariate logistic regression analysis showed that baseline LVEF was the only independent predictor and baseline LVEF < 48% predictive of significant LV dyssynchrony during RV pacing.The extent of RV pacing-induced LV dysfunction may be associated with baseline LV function. These adverse effects on patients with mildly reduced LVEF of 35-50% and indications for RV pacing due to bradycardia can thus be prevented by CRT.

Clinical validation of the planar radionuclide ventriculography in patients with right ventricular dysfunction.

PubMed

Bontemps, L; Merabet, Y; Chevalier, P; Itti, R

2013-01-01

Gated radionuclide ventriculography (RNV) may be used for the evaluation of the right ventricular function. However, the accuracy of the method should be clinically validated in patients suffering from diseases with specific pathology of the right ventricle (RV) and with possible left ventricular (LV) interaction. Three groups of 15 patients each, diagnosed with arrhythmogenic right ventricular dysplasia (ARVD), pulmonary artery hypertension (PAH) or atrial septal defect (ASD) were compared to a group of normal subjects. The parameters for both ventricles were evaluated separately (ejection fractions: LVEF and RVEF, and intraventricular synchronism quantified as phase standard deviation: LVPSD and RVPSD) as well as the relation or interdependence of the right to left ventricle (RV/LV volume ratio, LV/RV ejection fraction and stroke volume ratios, and interventricular synchronism). All the variables as a whole were analyzed to identify groups of patients according to their functional behaviour. Significant differences were found between the patients and control group for the RV function while the LV function remained mostly within normal limits. When the RV function was considered, the control group and ASD patient group showed differences regarding the ARVD and PAH patients. On evaluating the RV/LV ratios, differences were found between the control group and the ASD group. In the PAH patients, LV function showed differences in relation to the rest of the groups. RNV is a reliable clinical tool to evaluate RV function in patients with RV abnormality. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

Adiponectin, insulin resistance, and left ventricular structure in dipper and nondipper essential hypertensive patients.

PubMed

Della Mea, Paolo; Lupia, Mario; Bandolin, Valentina; Guzzon, Samuele; Sonino, Nicoletta; Vettor, Roberto; Fallo, Francesco

2005-01-01

Adiponectin is an adipocyte-derived protein with insulin-sensitizing and antiatherogenic properties. Failure to decrease blood pressure (BP) normally during night in hypertensive patients has been independently associated with left ventricular hypertrophy. We examined the relationship between adiponectin levels, insulin sensitivity, and left ventricular structure in 40 newly diagnosed never-treated patients with essential hypertension, including 20 patients with a normal night-time pressure decrease (ie, dippers) and 20 patients with BP persistently elevated throughout the 24-h period (ie, nondippers). All subjects had grade 1-2 hypertension, aged 18 to 65 years, no diabetes mellitus, no obesity, no hyperlipidemia, and no cardiopulmonary, renal, or hepatic disease. The two groups of patients were similar for age, sex, body mass index, and had no differences for clinic, 24-h, and diurnal BP, and 24-h, diurnal, and nocturnal heart rate, as well as glucose, total cholesterol, and triglyceride levels. Plasma insulin and homeostasis model assessment (HOMA index) were higher (P < .01), and adiponectin levels were lower (P < .005) in nondippers than in dippers. Adiponectin correlated inversely with HOMA index and insulin levels (r = -0.58, and r = -0.62, respectively, P < .001) in the entire population. Nondippers showed left ventricular mass, relative wall thickness, and measure of early and late diastolic peak flow velocity ratio similar to those of dippers. In the absence of major cardiovascular risk factors, nondipper essential hypertensive patients show more prominent insulin resistance and lower adiponectin compared to dippers. Therapeutic modulation of adiponectin or insulin resistance might provide additional benefit to the conventional antihypertensive treatment.

Premorbid determinants of left ventricular dysfunction in a novel model of gradually induced pressure overload in the adult canine

NASA Technical Reports Server (NTRS)

Koide, M.; Nagatsu, M.; Zile, M. R.; Hamawaki, M.; Swindle, M. M.; Keech, G.; DeFreyte, G.; Tagawa, H.; Cooper, G. 4th; Carabello, B. A.

1997-01-01

BACKGROUND: When a pressure overload is placed on the left ventricle, some patients develop relatively modest hypertrophy whereas others develop extensive hypertrophy. Likewise, the occurrence of contractile dysfunction also is variable. The cause of this heterogeneity is not well understood. METHODS AND RESULTS: We recently developed a model of gradual proximal aortic constriction in the adult canine that mimicked the heterogeneity of the hypertrophic response seen in humans. We hypothesized that differences in outcome were related to differences present before banding. Fifteen animals were studied initially. Ten developed left ventricular dysfunction (dys group). Five dogs maintained normal function (nl group). At baseline, the nl group had a lower mean systolic wall stress (96 +/- 9 kdyne/cm2; dys group, 156 +/- 7 kdyne/cm2; P < .0002) and greater relative left ventricular mass (left ventricular weight [g]/body wt [kg], 5.1 +/- 0.36; dys group, 3.9 +/- 0.26; P < .02). On the basis of differences in mean systolic wall stress at baseline, we predicted outcome in the next 28 dogs by using a cutoff of 115 kdyne/cm2. Eighteen of 20 dogs with baseline mean systolic stress > 115 kdyne/cm2 developed dysfunction whereas 6 of 8 dogs with resting stress < or = 115 kdyne/cm2 maintained normal function. CONCLUSIONS: We conclude that this canine model mimicked the heterogeneous hypertrophic response seen in humans. In the group that eventually developed dysfunction there was less cardiac mass despite 60% higher wall stress at baseline, suggesting a different set point for regulating myocardial growth in the two groups.

Muscle remodeling in relation to blood supply: implications for seasonal changes in mitochondrial enzymes.

PubMed

McClelland, G B; Dalziel, A C; Fragoso, N M; Moyes, C D

2005-02-01

We investigated if seasonal changes in rainbow trout muscle energetics arise in response to seasonal changes in erythrocyte properties. We assessed if skeletal muscle mitochondrial enzymes changed (1) acutely in response to changes in erythrocyte abundance, or (2) seasonally when we altered the age profile of erythrocytes. Rainbow trout were treated with pheynylhydrazine, causing a 75% reduction in hematocrit within 4 days. After erythropoiesis had returned hematocrit to normal, treated and control fish were subjected to a seasonal cold acclimation regime to assess the impact of erythrocyte age on skeletal muscle remodeling. Anemia (i.e. phenylhydrazine treatment) did not alter the specific activities (U g(-1) tissue) of mitochondrial enzymes in white or red muscle. Anemic pretreatment did not alter the normal pattern of cold-induced mitochondrial proliferation in skeletal muscle, suggesting erythrocyte age was not an important influence on seasonal remodeling of muscle. Anemia and cold acclimation both induced a 25-30% increase in relative ventricular mass. The increase in relative ventricular mass with phenylhydrazine treatment was accompanied by a 35% increase in DNA content (mg DNA per ventricle), suggesting an increase in number of cells. In contrast, the increase in ventricular mass with cold temperature acclimation occurred without a change in DNA content (mg DNA per ventricle), suggesting an increase in cell size. Despite the major increases in relative ventricular mass, neither anemia nor seasonal acclimation had a major influence on the specific activities of a suite of mitochondrial enzymes in heart. Collectively, these studies argue against a role for erythrocyte dynamics in seasonal adaptive remodeling of skeletal muscle energetics.

Atrioventricular valve repair in patients with functional single-ventricle physiology: impact of ventricular and valve function and morphology on survival and reintervention.

PubMed

Honjo, Osami; Atlin, Cori R; Mertens, Luc; Al-Radi, Osman O; Redington, Andrew N; Caldarone, Christopher A; Van Arsdell, Glen S

2011-08-01

This study was to determine whether atrioventricular valve repair modifies natural history of single-ventricle patients with atrioventricular valve insufficiency and to identify factors predicting survival and reintervention. Fifty-seven (13.5%) of 422 single-ventricle patients underwent atrioventricular valve repair. Valve morphology, regurgitation mechanism, and ventricular morphology and function were analyzed for effect on survival, transplant, and reintervention with multivariate logistic and Cox regression models. Comparative analysis used case-matched controls. Atrioventricular valve was tricuspid in 67% and common in 28%. Ventricular morphology was right in 83%. Regurgitation mechanisms were prolapse (n = 24, 46%), dysplasia (n = 18, 35%), annular dilatation (n = 8, 15%), and restriction or cleft (n = 2, 4%). Postrepair insufficiency was none or trivial in 14 (26%), mild in 33 (61%), and moderate in 7 (13%). Survival in repair group was lower than in matched controls (78.9% vs 92.7% at 1 year, 68.7% vs 90.6% at 3 years, P = .015). Patients with successful repair and normal ventricular function had equivalent survival to matched controls (P = .36). Independent predictors for death or transplant included increased indexed annular size (P = .05), increased cardiopulmonary bypass time (P = .04), and decreased postrepair ventricular function (P = .01). Ventricular dilation was a time-related factor for all events, including failed repair. Survival was lower in single-ventricle patients operated on for atrioventricular valve insufficiency than in case-matched controls. Patients with little postoperative residual regurgitation and preserved ventricular function had equivalent survival to controls. Lower grade ventricular function and ventricular dilation correlated with death and repair failure, suggesting that timing of intervention may affect outcome. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Effect of Loss of Heart Rate Variability on T-Wave Heterogeneity and QT Variability in Heart Failure Patients: Implications in Ventricular Arrhythmogenesis.

PubMed

Nayyar, Sachin; Hasan, Muhammad A; Roberts-Thomson, Kurt C; Sullivan, Thomas; Baumert, Mathias

2017-06-01

Heart rate variability (HRV) modulates dynamics of ventricular repolarization. A diminishing value of HRV is associated with increased vulnerability to life-threatening ventricular arrhythmias, however the causal relationship is not well-defined. We evaluated if fixed-rate atrial pacing that abolishes the effect of physiological HRV, will alter ventricular repolarization wavefronts and is relevant to ventricular arrhythmogenesis. The study was performed in 16 subjects: 8 heart failure patients with spontaneous ventricular tachycardia [HFVT], and 8 subjects with structurally normal hearts (H Norm ). The T-wave heterogeneity descriptors [total cosine angle between QRS and T-wave loop vectors (TCRT, negative value corresponds to large difference in the 2 loops), T-wave morphology dispersion, T-wave loop dispersion] and QT intervals were analyzed in a beat-to-beat manner on 3-min records of 12-lead surface ECG at baseline and during atrial pacing at 80 and 100 bpm. The global T-wave heterogeneity was expressed as mean values of each of the T-wave morphology descriptors and variability in QT intervals (QTV) as standard deviation of QT intervals. Baseline T-wave morphology dispersion and QTV were higher in HFVT compared to H Norm subjects (p ≤ 0.02). While group differences in T-wave morphology dispersion and T-wave loop dispersion remained unaltered with atrial pacing, TCRT tended to fall more in HFVT patients compared to H Norm subjects (interaction p value = 0.086). Atrial pacing failed to reduce QTV in both groups, however group differences were augmented (p < 0.0001). Atrial pacing and consequent loss of HRV appears to introduce unfavorable changes in ventricular repolarization in HFVT subjects. It widens the spatial relationship between wavefronts of ventricular depolarization and repolarization. This may partly explain the concerning relation between poorer HRV and the risk of ventricular arrhythmias.

Cardiovascular magnetic resonance of cardiac function and myocardial mass in preterm infants: a preliminary study of the impact of patent ductus arteriosus

PubMed Central

2014-01-01

Background Many pathologies seen in the preterm population are associated with abnormal blood supply, yet robust evaluation of preterm cardiac function is scarce and consequently normative ranges in this population are limited. The aim of this study was to quantify and validate left ventricular dimension and function in preterm infants using cardiovascular magnetic resonance (CMR). An initial investigation of the impact of the common congenital defect patent ductus arteriosus (PDA) was then carried out. Methods Steady State Free Procession short axis stacks were acquired. Normative ranges of left ventricular end diastolic volume (EDV), stroke volume (SV), left ventricular output (LVO), ejection fraction (EF), left ventricular (LV) mass, wall thickness and fractional thickening were determined in “healthy” (control) neonates. Left ventricular parameters were then investigated in PDA infants. Unpaired student t-tests compared the 2 groups. Multiple linear regression analysis assessed impact of shunt volume in PDA infants, p-value ≤ 0.05 being significant. Results 29 control infants median (range) corrected gestational age at scan 34+6(31+1-39+3) weeks were scanned. EDV, SV, LVO, LV mass normalized by weight and EF were shown to decrease with increasing corrected gestational age (cGA) in controls. In 16 PDA infants (cGA 30+3(27+3-36+1) weeks) left ventricular dimension and output were significantly increased, yet there was no significant difference in ejection fraction and fractional thickening between the two groups. A significant association between shunt volume and increased left ventricular mass correcting for postnatal age and corrected gestational age existed. Conclusion CMR assessment of left ventricular function has been validated in neonates, providing more robust normative ranges of left ventricular dimension and function in this population. Initial investigation of PDA infants would suggest that function is relatively maintained. PMID:25160730

Right Heart Vorticity and Right Ventricular Diastolic Dysfunction

NASA Astrophysics Data System (ADS)

Browning, James; Hertzberg, Jean; Fenster, Brett; Schroeder, Joyce

2015-11-01

Recent advances in cardiac magnetic resonance imaging (CMR) have allowed for the 3-dimensional characterization of blood flow in the right ventricle (RV) and right atrium (RA). In this study, we investigate and quantify differences in the characteristics of coherent rotating flow structures (vortices) in the RA and RV between subjects with right ventricular diastolic dysfunction (RVDD) and normal controls. Fifteen RVDD subjects and 10 age-matched controls underwent same day 3D time resolved CMR and echocardiography. Echocardiography was used to determine RVDD stage as well as pulmonary artery systolic pressure (PASP). CMR data was used for RA and RV vortex quantification and visualization during early ventricular diastole and the results are compared between healthy subjects and those with RVDD. The resulting trends are discussed and hypotheses are presented regarding differences in vortex characteristics between healthy and RVDD subjects cohorts.

Tumor necrosis factor and interleukin-6 levels in hypertensive patients with and without left ventricular hypertrophy.

PubMed

Leibowitz, David; Planer, David; Ben-Ivgi, Fanny; Weiss, A Teddy; Bursztyn, Michael

2005-01-01

The objective of this prospective study was to examine the association between serum levels of TNF (tumor-necrosis factor) and IL-6 (interleukin-6) and left ventricular mass in hypertensive patients. Hypertensive patients currently receiving medical therapy were eligible. All subjects underwent echocardiography with measurements of left ventricular (LV) mass and ejection fraction (EF) and had serum levels of TNF and IL-6 measured by ELISA immunoassay. 35 subjects (20F, 15M; mean age 56.4 +/- 10.5 yrs) were studied. 19 patients (54%) had elevated LV mass. Of these patients, 6 (32%) had detectable serum TNF levels and 1 (7%) had detectable IL-6 levels, (p = NS). Hypertensive patients with elevated LV mass do not consistently exhibit elevated cytokine levels when compared to those with normal LV mass.

Unipolar Endocardial Voltage Mapping in the Right Ventricle: Optimal Cutoff Values Correcting for Computed Tomography-Derived Epicardial Fat Thickness and Their Clinical Value for Substrate Delineation.

PubMed

Venlet, Jeroen; Piers, Sebastiaan R D; Kapel, Gijsbert F L; de Riva, Marta; Pauli, Philippe F G; van der Geest, Rob J; Zeppenfeld, Katja

2017-08-01

Low endocardial unipolar voltage (UV) at sites with normal bipolar voltage (BV) may indicate epicardial scar. Currently applied UV cutoff values are based on studies that lacked epicardial fat information. This study aimed to define endocardial UV cutoff values using computed tomography-derived fat information and to analyze their clinical value for right ventricular substrate delineation. Thirty-three patients (50±14 years; 79% men) underwent combined endocardial-epicardial right ventricular electroanatomical mapping and ablation of right ventricular scar-related ventricular tachycardia with computed tomographic image integration, including computed tomography-derived fat thickness. Of 6889 endocardial-epicardial mapping point pairs, 547 (8%) pairs with distance <10 mm and fat thickness <1.0 mm were analyzed for voltage and abnormal (fragmented/late potential) electrogram characteristics. At sites with endocardial BV >1.50 mV, the optimal endocardial UV cutoff for identification of epicardial BV <1.50 mV was 3.9 mV (area under the curve, 0.75; sensitivity, 60%; specificity, 79%) and cutoff for identification of abnormal epicardial electrogram was 3.7 mV (area under the curve, 0.88; sensitivity, 100%; specificity, 67%). The majority of abnormal electrograms (130 of 151) were associated with transmural scar. Eighty-six percent of abnormal epicardial electrograms had corresponding endocardial sites with BV <1.50 mV, and the remaining could be identified by corresponding low endocardial UV <3.7 mV. For identification of epicardial right ventricular scar, an endocardial UV cutoff value of 3.9 mV is more accurate than previously reported cutoff values. Although the majority of epicardial abnormal electrograms are associated with transmural scar with low endocardial BV, the additional use of endocardial UV at normal BV sites improves the diagnostic accuracy resulting in identification of all epicardial abnormal electrograms at sites with <1.0 mm fat. © 2017 American Heart Association, Inc.

Importance of rate control or rate regulation for improving exercise capacity and quality of life in patients with permanent atrial fibrillation and normal left ventricular function: a randomised controlled study

PubMed Central

Levy, T; Walker, S; Mason, M; Spurrell, P; Rex, S; Brant, S; Paul, V

2001-01-01

OBJECTIVE—To determine the importance of rhythm regulation or rate control in patients with permanent atrial fibrillation (AF) and normal left ventricular function.
PATIENTS AND INTERVENTIONS—Thirty six patients with a mixed fast and slow ventricular response rate to their AF were randomised to either His bundle ablation (HBA) and VVIR pacemaker (HBA group) or VVI pacemaker and atrioventricular modifying drugs (Med group). Outcomes assessed at one, three, six, and 12 months included exercise duration and quality of life.
RESULTS—Exercise duration significantly improved from baseline in both groups. There was no difference in outcome between the groups (Med +40% v HBA +20%, p = NS). The heart rate profile on exercise was similarly slowed in both groups compared to baseline. Quality of life significantly improved in both treatment arms for the modified Karolinska questionnaire (KQ) (Med +50% v HBA +50%, p = NS) and the Nottingham health profile (NHP) (Med +40% v HBA +20%, p = NS). However, for the individual symptom scores of each questionnaire more were improved in the Med group (KQ-Med 6 improved v HBA 4, NHP-Med 3 v HBA 1). Left ventricular function was equally preserved by both treatments during follow up.
CONCLUSION—In these patients control of ventricular response rate with either HBA + VVIR pacemaker or atrioventricular modifying drugs + VVI pacemaker will lead to a significant improvement in exercise duration and quality of life. Rhythm regulation by HBA did not confer additional benefit, suggesting rate control alone is necessary for the successful symptomatic treatment of these patients in permanent AF.


Keywords: ablation; atrial fibrillation; pacemaker; atrioventricular modifying drugs PMID:11156667

Are controls in schizophrenia research "normal"?

PubMed

Olson, S C; Bornstein, R A; Schwarzkopf, S B; Nasrallah, H A

1993-03-01

The psychiatric assessment by structured interview and family history of mental disorder in normal volunteers recruited by advertisement for a study of brain structure and function in psychosis is described. Nine of 51 volunteers (17.6%) who passed a phone screen were excluded after a structured interview for major psychopathology. Of 35 completers, 10 (28.6%) had subthreshold mood or substance use but were included in the study. Only 16 subjects (45%) had a negative family history by FH-RDC. Diagnoses in family members included substance abuse (31%), mood disorder (11%), psychosis (9%), and other/undiagnosed (14%). Ventricular enlargement was evaluated by magnetic resonance imaging in two planes. Ventricular size was bimodally distributed in the males, and the group with larger ventricles was more educated and had higher scores on the 8 (Schizophrenia) scale of the MMPI (F = 5.44, p = .0099). Our results suggest that 'normal' volunteers for psychiatric research have personal or family psychopathology which motivates them to participate. As the sensitivity of biological instrumentation increases, the characteristics of the control group must be anticipated in the design and recruitment.

Increased chymase-like activity in a dog with congenital pulmonic stenosis.

PubMed

Fujii, Yoko; Yamane, Tsuyoshi; Orito, Kensuke; Osamura, Kaori; Wakao, Yoshito

2007-05-01

This study was intended to compare the tissue chymase-like activity and angiotensin converting enzyme (ACE) activity in the right and left ventricles of a dog with congenital pulmonic stenosis (PS), with normal dogs, and to discuss the potential clinical implications of these findings. Study subjects included a one-year-old Beagle dog with spontaneous PS and six clinically normal Beagles. Chymase-like and ACE activities were determined in all hearts by high pressure liquid chromatography. In the PS dog right ventricular (RV) chymase-like activity (49.79 nmol/min/g tissue) and left ventricular (LV) chymase-like activity (36.85 nmol/min/g tissue) were elevated vs normal Beagle dogs (mean+/-standard deviation, RV: 20.17+/-5.24 nmol/min/g, LV: 19.03+/-3.27 nmol/min/g). Activation of the tissue RAA system was detected in a dog with congenital PS. This interesting finding should be pursued with further studies to validate this result, and to explore whether pharmacological blockade of chymase, or the angiotensin II receptor, represents a useful strategy to prevent myocardial remodeling in this condition.

Ventricular enlargement as a possible measure of Alzheimer's disease progression validated using the Alzheimer's disease neuroimaging initiative database

PubMed Central

Nestor, Sean M.; Rupsingh, Raul; Borrie, Michael; Smith, Matthew; Accomazzi, Vittorio; Wells, Jennie L.; Fogarty, Jennifer

2008-01-01

Ventricular enlargement may be an objective and sensitive measure of neuropathological change associated with mild cognitive impairment (MCI) and Alzheimer's disease (AD), suitable to assess disease progression for multi-centre studies. This study compared (i) ventricular enlargement after six months in subjects with MCI, AD and normal elderly controls (NEC) in a multi-centre study, (ii) volumetric and cognitive changes between Apolipoprotein E genotypes, (iii) ventricular enlargement in subjects who progressed from MCI to AD, and (iv) sample sizes for multi-centre MCI and AD studies based on measures of ventricular enlargement. Three dimensional T1-weighted MRI and cognitive measures were acquired from 504 subjects (NEC n = 152, MCI n = 247 and AD n = 105) participating in the multi-centre Alzheimer's Disease Neuroimaging Initiative. Cerebral ventricular volume was quantified at baseline and after six months using semi-automated software. For the primary analysis of ventricle and neurocognitive measures, between group differences were evaluated using an analysis of covariance, and repeated measures t-tests were used for within group comparisons. For secondary analyses, all groups were dichotomized for Apolipoprotein E genotype based on the presence of an ε4 polymorphism. In addition, the MCI group was dichotomized into those individuals who progressed to a clinical diagnosis of AD, and those subjects that remained stable with MCI after six months. Group differences on neurocognitive and ventricle measures were evaluated by independent t-tests. General sample size calculations were computed for all groups derived from ventricle measurements and neurocognitive scores. The AD group had greater ventricular enlargement compared to both subjects with MCI (P = 0.0004) and NEC (P < 0.0001), and subjects with MCI had a greater rate of ventricular enlargement compared to NEC (P = 0.0001). MCI subjects that progressed to clinical AD after six months had greater ventricular enlargement than stable MCI subjects (P = 0.0270). Ventricular enlargement was different between Apolipoprotein E genotypes within the AD group (P = 0.010). The number of subjects required to demonstrate a 20% change in ventricular enlargement was substantially lower than that required to demonstrate a 20% change in cognitive scores. Ventricular enlargement represents a feasible short-term marker of disease progression in subjects with MCI and subjects with AD for multi-centre studies. PMID:18669512

Right Ventricular Tissue Doppler in Space Flight

NASA Technical Reports Server (NTRS)

Garcia, Kathleen M.; Hamilton, Douglas R.; Sargsyan, Ashot E.; Ebert, Douglas; Martin, David S.; Barratt, Michael R.; Martin, David S.; Bogomolov, Valery V.; Dulchavsky, Scott A.; Duncan, J. Michael

2010-01-01

The presentation slides review normal physiology of the right ventricle in space, general physiology of the right ventricle; difficulties in imaging the heart in space, imaging methods, tissue Doppler spectrum, right ventricle tissue Doppler, and Rt Tei Index.

Pulmonary hypertension and right heart failure due to severe hypernatremic dehydration.

PubMed

Chiwane, Saurabh; Ahmed, Tageldin M; Bauerfeld, Christian P; Chauhan, Monika

2017-07-01

Neonates are at risk of developing hypernatremic dehydration and its associated complications, such as stroke, dural sinus thrombosis and renal vein thrombosis. Pulmonary hypertension has not been described as a complication of hypernatremia. We report a case of a seven-day-old neonate with severe hypernatremic dehydration who went on to develop pulmonary hypertension and right heart failure needing extracorporeal membrane oxygenation (ECMO). Normal or high anion gap metabolic acidosis commonly accompanies hypernatremic dehydration. The presence of acidosis and/or hypoxia can delay the normal drop in pulmonary vascular resistance (PVR) after birth, causing pulmonary hypertension and right ventricular failure. A high index of suspicion is paramount to diagnose pulmonary hypertension and aggressive correction of the acidosis and hypoxia is needed. In the presence of severe right ventricular failure, ECMO can be used as a bridge to recovery while underlying metabolic derangements are being corrected.

[Takotsubo cardiomyopathy in the context of Staphylococcus aureus sepsis].

PubMed

Núñez, D; Bermejo, R; Rodríguez-Velasco, A

2014-03-01

Takotsubo cardiomyopathy consists of a transient dysfunction of the left ventricle. It is characterised by an impaired left ventricular segmentary contractility, without significant coronary lesions in the coronary angiography. It usually occurs after an episode of physical or emotional stress. We present the case of a 70 year-old woman, who, in the postoperative period of an ankle osteosynthesis, developed a Takotsubo cardiomyopathy in the context of a sepsis caused by Staphylococcus aureus. She presented with acute lung oedema and a clinical picture of low cardiac output. The echocardiogram showed left ventricular medioapical akinesia. Coronary angiography was normal. She was treated with supportive measures with good progress. At 33 days from onset she was able to be discharged from hospital to home with normal systolic function on echocardiography. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Late myocardial ischemia with ST-segment elevation after negative dobutamine stress echocardiography in a patient with normal coronary arteries.

PubMed

Cabani, Enrico; Lattanzi, Fabio; Paci, Anna Maria; Pieroni, Andrea; Baria, Luca; Tommasi, Salvatore Mario De

2009-04-01

Late complications after pharmacological stress echocardiography are infrequent but potentially dreadful events. We report the case of a 80-year-old woman admitted to hospital for rest chest pain with trivial troponin increase, normal left ventricular function and no significant ECG changes. A dobutamine stress echocardiography was performed for diagnostic purpose, with a negative result. About 30 min after the end of dobutamine infusion, she developed ST-segment elevation in inferior leads associated with chest pain and left ventricular dyssynergy, promptly resolved by sublingual nitrates. Subsequently, angiography documented the absence of significant coronary stenoses. The following clinical course was uneventful. Transient myocardial ischemia was likely due to dobutamine-induced coronary spasm. The case emphasizes the utility of routine, long-lasting monitoring of patients after stress echocardiography, even if negative, to counteract possible late life-threatening complications.

Prognostic implications of left ventricular mass and geometry following myocardial infarction: the VALIANT (VALsartan In Acute myocardial iNfarcTion) Echocardiographic Study.

PubMed

Verma, Anil; Meris, Alessandra; Skali, Hicham; Ghali, Jalal K; Arnold, J Malcolm O; Bourgoun, Mikhail; Velazquez, Eric J; McMurray, John J V; Kober, Lars; Pfeffer, Marc A; Califf, Robert M; Solomon, Scott D

2008-09-01

This study sought to understand prognostic implications of increased baseline left ventricular (LV) mass and geometric patterns in a high risk acute myocardial infarction. The LV hypertrophy and alterations in LV geometry are associated with an increased risk of adverse cardiovascular events. Quantitative echocardiographic analyses were performed at baseline in 603 patients from the VALIANT (VALsartan In Acute myocardial iNfarcTion) echocardiographic study. The left ventricular mass index (LVMi) and relative wall thickness (RWT) were calculated. Patients were classified into 4 mutually exclusive groups based on RWT and LVMi as follows: normal geometry (normal LVMi and normal RWT), concentric remodeling (normal LVMi and increased RWT), eccentric hypertrophy (increased LVMi and normal RWT), and concentric hypertrophy (increased LVMi and increased RWT). Cox proportional hazards models were used to evaluate the relationships among LVMi, RWT, LV geometry, and clinical outcomes. Mean LVMi and RWT were 98.8 +/- 28.4 g/m(2) and 0.38 +/- 0.08. The risk of death or the composite end point of death from cardiovascular causes, reinfarction, heart failure, stroke, or resuscitation after cardiac arrest was lowest for patients with normal geometry, and increased with concentric remodeling (hazard ratio [HR]: 3.0; 95% confidence interval [CI]: 1.9 to 4.9), eccentric hypertrophy (HR: 3.1; 95% CI: 1.9 to 4.8), and concentric hypertrophy (HR: 5.4; 95% CI: 3.4 to 8.5), after adjusting for baseline covariates. Also, baseline LVMi and RWT were associated with increased mortality and nonfatal cardiovascular outcomes (HR: 1.22 per 10 g/m(2) increase in LVMi; 95% CI: 1.20 to 1.30; p < 0.001) (HR: 1.60 per 0.1-U increase in RWT; 95% CI: 1.30 to 1.90; p < 0.001). Increased risk associated with RWT was independent of LVMi. Increased baseline LV mass and abnormal LV geometry portend an increased risk for morbidity and mortality following high-risk myocardial infarction. Concentric LV hypertrophy carries the greatest risk of adverse cardiovascular events including death. Higher RWT was associated with an increased risk of cardiovascular complications after high-risk myocardial infarction.

Right Ventricular Failure Post LVAD Implantation Corrected with Biventricular Support: An In Vitro Model.

PubMed

Shehab, Sajad; Allida, Sabine M; Davidson, Patricia M; Newton, Phillip J; Robson, Desiree; Jansz, Paul C; Hayward, Christopher S

Right ventricular failure after left ventricular assist device (LVAD) implantation is associated with high mortality. Management remains limited to pharmacologic therapy and temporary mechanical support. Delayed right ventricular assist device (RVAD) support after LVAD implantation is associated with poorer outcomes. With the advent of miniaturized, durable, continuous flow ventricular assist device systems, chronic RVAD and biventricular assist device (BiVAD) support has been used with some success. The purpose of this study was to assess combined BiVAD and LVAD with delayed RVAD support within a four-elemental mock circulatory loop (MCL) simulating the human cardiovascular system. Our hypothesis was that delayed continuous flow RVAD (RVAD) would produce similar hemodynamic and flow parameters to those of initial BiVAD support. Using the MCL, baseline biventricular heart failure with elevated right and left filling pressures with low cardiac output was simulated. The addition of LVAD within a biventricular configuration improved cardiac output somewhat, but was associated with persistent right heart failure with elevated right-sided filling pressures. The addition of an RVAD significantly improved LVAD outputs and returned filling pressures to normal throughout the circulation. In conclusion, RVAD support successfully restored hemodynamics and flow parameters of biventricular failure supported with isolated LVAD with persistent elevated right atrial pressure.

Reversion of left ventricular systolic dysfunction and abnormal stress test: by catheter ablation, in a patient with Wolff-Parkinson-White syndrome from Para-Hisian Kent bundle.

PubMed

Tu, Chung-Ming; Chu, Kai-Ming; Cheng, Cheng-Chung; Cheng, Shu-Mung; Lin, Wei-Shiang

2010-01-01

The diagnosis of Wolff-Parkinson-White syndrome is typically reserved for patients who experience ventricular pre-excitation and symptoms that are related to paroxysmal supraventricular tachycardia, such as chest pain, dyspnea, dizziness, palpitations, or syncope. Herein, we report the case of a 38-year-old woman who presented at our outpatient department because of exercise intolerance. Cardiac auscultation revealed a grade 2/6 pansystolic murmur over the left lower sternal border. Twelve-lead electrocardiography showed sinus rhythm at a rate of 76 beats/min, with a significant delta wave. Transthoracic echocardiography revealed abnormal left ventricular systolic function. The results of a thallium stress test were also abnormal. Coronary artery disease was suspected; however, coronary angiography yielded normal results. Electrophysiologic study revealed a para-Hisian Kent bundle and a dual atrioventricular nodal pathway. After radiofrequency catheter ablation was performed, the patient's left ventricular function improved and her symptoms disappeared. In Wolff-Parkinson-White syndrome, left ventricular systolic dyssynchrony can yield abnormal findings on echocardiography and thallium scanning--even in persons who have no cardiovascular risk factors. Physicians who are armed with this knowledge can avoid performing coronary angiography unnecessarily. Catheter ablation can reverse the dyssynchrony of the ventricle and improve the patient's symptoms.

Comparison of ventricular and lumbar cerebrospinal fluid T cells in non-inflammatory neurological disorder (NIND) patients.

PubMed

Provencio, J Javier; Kivisäkk, Pia; Tucky, Barbara H; Luciano, Mark G; Ransohoff, Richard M

2005-06-01

The aim of the present study was to define the cellular composition of ventricular, as compared with lumbar, cerebrospinal fluid (CSF) in patients with non-inflammatory neurological disorders (NIND). We addressed this issue by determining the cellular composition of lumbar CSF from patients with normal pressure hydrocephalus (NPH) who were undergoing lumbar CSF drainage during evaluation for shunting procedures, and evaluating ventricular CSF from a subset of these who underwent subsequent placement of ventriculoperitoneal shunts. We determined the cellular composition of lumbar CSF from 18 patients with NPH, and found that the leukocyte differentials, and relative proportions of CD4+ and CD8+ central memory (TCM), effector memory (TEM) and naive cell (TNaive) populations, were equivalent to those found previously in studies of CSF from patients with NIND. We further evaluated cells in the ventricular CSF of five patients who had previously undergone lumbar drainage. Leukocyte differential counts, as well as CD4+ and CD8+ TCM, TEM, and TNaive proportions, were equivalent in matched ventricular and lumbar CSF samples. These observations support the hypothesis that leukocytes enter the CSF in a selective fashion, at its site of formation in the choroid plexus. The results implicate CSF T cells in the immune surveillance of the central nervous system.

Effect of right ventricular pacing on cardiac apex rotation assessed by a gyroscopic sensor.

PubMed

Marcelli, Emanuela; Cercenelli, Laura; Parlapiano, Mario; Fumero, Roberto; Bagnoli, Paola; Costantino, Maria Laura; Plicchi, Gianni

2007-01-01

To quantify cardiac apex rotation (CAR), the authors recently proposed the use of a Coriolis force sensor (gyroscope) as an alternative to other complex techniques. The aim of this study was to evaluate the effects of right ventricular (RV) pacing on CAR. A sheep heart was initially paced from the right atrium to induce a normal activation sequence at a fixed heart rate (AAI mode) and then an atrioventricular pacing was performed (DOO mode, AV delay = 60 ms). A small gyroscope was epicardially glued on the cardiac apex to measure the angular velocity (Ang V). From AAI to DOO pacing mode, an increase (+9.2%, p < 0.05) of the maximum systolic twisting velocity (Ang VMAX) and a marked decrease (-19.9%, p < 0.05) of the maximum diastolic untwisting velocity (Ang VMIN) resulted. RV pacing had negligible effects (-3.1%, p = 0.09) on the maximum angle of CAR, obtained by integrating Ang V. The hemodynamic parameters of systolic (LVdP/dtMAX) and diastolic (LVdP/dtMIN) cardiac function showed slight variations (-3.8%, p < 0.05 and +3.9%, p < 0.05, respectively). Results suggest that cardiac dyssynchrony induced by RV pacing can alter the normal physiological ventricular twist patterns, particularly affecting diastolic untwisting velocity.

Tissue Doppler, strain, and strain rate echocardiography for the assessment of left and right systolic ventricular function

PubMed Central

Pellerin, D; Sharma, R; Elliott, P; Veyrat, C

2003-01-01

Tissue Doppler (TDE), strain, and strain rate echocardiography are emerging real time ultrasound techniques that provide a measure of wall motion. They offer an objective means to quantify global and regional left and right ventricular function and to improve the accuracy and reproducibility of conventional echocardiography studies. Radial and longitudinal ventricular function can be assessed by the analysis of myocardial wall velocity and displacement indices, or by the analysis of wall deformation using the rate of deformation of a myocardial segment (strain rate) and its deformation over time (strain). A quick and easy assessment of left ventricular ejection fraction is obtained by mitral annular velocity measurement during a routine study, especially in patients with poor endocardial definition or abnormal septal motion. Strain rate and strain are less affected by passive myocardial motion and tend to be uniform throughout the left ventricle in normal subjects. This paper reviews the underlying principles of TDE, strain, and strain rate echocardiography and discusses currently available quantification tools and clinical applications. PMID:14594870

Application of MR virtual endoscopy in children with hydrocephalus.

PubMed

Zhao, Cailei; Yang, Jian; Gan, Yungen; Liu, Jiangang; Tan, Zhen; Liang, Guohua; Meng, Xianlei; Sun, Longwei; Cao, Weiguo

2015-12-01

To evaluate the performance of MR virtual endoscopy (MRVE) in children with hydrocephalus. Clinical and imaging data were collected from 15 pediatric patients with hydrocephalus and 15 normal control children. All hydrocephalus patients were confirmed by ventriculoscopy or CT imaging. The cranial 3D-T1 weighted imaging data from fast spoiled gradient echo scan (FSPGR) were transported to working station. VE images of cerebral ventricular cavity were constructed with Navigator software. Cerebral ventricular MRVE can achieve similar results as ventriculoscopy in demonstrating the morphology of ventricular wall or intracavity lesion. In addition, MRVE can observe the lesion from distal end of obstruction, as well as other areas that are inaccessible to ventriculoscopy. MRVE can also reveal the pathological change of ventricular inner wall surface, and help determine patency of the cerebral aqueduct and fourth ventricle outlet. MR virtual endoscopy provides a non-invasive diagnostic modality that can be used as a supplemental approach to ventriculoscopy. However, its sensitivity and specificity need to be determined in the large study. Copyright © 2015 Elsevier Inc. All rights reserved.

Noninvasive beat-by-beat registration of ventricular late potentials using high resolution electrocardiography.

PubMed

Hombach, V; Kebbel, U; Höpp, H W; Winter, U; Hirche, H

1984-08-01

We have developed a new high resolution ECG equipment for recording cardiac microvolt potentials from the body surface. Noise reduction has been achieved by specially designed suction electrodes, by spatial averaging of the electrocardiograms from four electrode pairs, using extremely low noise amplifiers, by performing registrations within a Faraday cage, and by teaching the patient to relax during end expiratory breath holding. Fourteen young males (controls) and 30 patients with various cardiac diseases (27 with CHD) were studied. In normals ventricular late potentials were not seen, but in 12/30 patients clearcut diastolic potentials were found. In 7/12 patients with positive findings, late potentials appeared beat-by-beat, in 5/12 patients those signals occurred intermittently, in 11/30 patients questionably, and in the remaining 5/30 patients no late potentials were recorded. One patient with the Romano-Ward syndrome revealed phases with stable beat-by-beat and intermittently occurring ventricular late potentials. These results demonstrate the feasibility of continuous non-invasive recording of ventricular late potentials, whose clinical and prognostic significance remains to be established.

Synchronous ventricular pacing with direct capture of the atrioventricular conduction system: Functional anatomy, terminology, and challenges.

PubMed

Mulpuru, Siva K; Cha, Yong-Mei; Asirvatham, Samuel J

2016-11-01

Right ventricular apical pacing is associated with an increased incidence of heart failure, atrial fibrillation, and overall mortality. As a result, pacing the ventricles in a manner that closely mimics normal AV conduction with an intact His-Purkinje system has been explored. Recently, the sustainable benefits of selective His-bundle stimulation have been demonstrated and proposed as the preferred method of ventricular stimulation for appropriate patients. Ideally, conduction system pacing should be selective without myocardial capture, overcome distal bundle branch block when present, and not compromise tricuspid valve function. Contemporary literature on conduction system pacing is confusing largely because of inconsistent terminology and, at times, anatomically inaccurate terms used interchangeably for nonsynonymous anatomic sites. In this review, we discuss the functional anatomy of AV conduction access with specific emphasis on terminology, relationship to the membranous septum, tricuspid valve tissue, and proximity to atrial or ventricular myocardium. The potential benefits of each specific site as well as associated unique difficulties with those sites are described. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Physiologic abnormalities of cardiac function in progressive systemic sclerosis with diffuse scleroderma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Follansbee, W.P.; Curtiss, E.I.; Medsger, T.A. Jr.

1984-01-19

To investigate cardiopulmonary function in progressive systemic sclerosis with diffuse scleroderma, we studied 26 patients with maximal exercise and redistribution thallium scans, rest and exercise radionuclide ventriculography, pulmonary-function testing, and chest roentgenography. Although only 6 patients had clinical evidence of cardiac involvement, 20 had abnormal thallium scans, including 10 with reversible exercise-induced defects and 18 with fixed defects (8 had both). Seven of the 10 patients who had exercise-induced defects and underwent cardiac catheterization had normal coronary angiograms. Mean resting left ventricular ejection fraction and mean resting right ventricular ejection fraction were lower in patients with post-exercise left ventricular thalliummore » defect scores above the median (59 +/- 13 per cent vs. 69 +/- 6 per cent, and 36 +/- 12 per cent vs. 47 +/- 7 per cent, respectively). The authors conclude that in progressive systemic sclerosis with diffuse scleroderma, abnormalities of myocardial perfusion are common and appear to be due to a disturbance of the myocardial microcirculation. Both right and left ventricular dysfunction appear to be related to this circulatory disturbance, suggesting ischemically mediated injury.« less

The influence of myocardial substrate on ventricular fibrillation waveform: A swine model of acute and postmyocardial infarction

PubMed Central

Indik, Julia H.; Donnerstein, Richard L.; Hilwig, Ronald W.; Zuercher, Mathias; Feigelman, Justin; Kern, Karl B.; Berg, Marc D.; Berg, Robert A.

2009-01-01

Objective In cardiac arrest resulting from ventricular fibrillation, the ventricular fibrillation waveform may be a clue to its duration and predict the likelihood of shock success. However, ventricular fibrillation occurs in different myocardial substrates such as ischemia, heart failure, and structurally normal hearts. We hypothesized that ventricular fibrillation is altered by myocardial infarction and varies from the acute to postmyocardial infarction periods. Design An animal intervention study was conducted with comparison to a control group. Setting This study took place in a university animal laboratory. Subjects Study subjects included 37 swine. Interventions Myocardial infarction was induced by occlusion of the midleft anterior descending artery. Ventricular fibrillation was induced in control swine, acute myocardial infarction swine, and in postmyocardial infarction swine after a 2-wk recovery period. Measurements and Main Results Ventricular fibrillation was recorded in 11 swine with acute myocardial infarction, ten post-myocardial infarction, and 16 controls. Frequency (mean, median, dominant, and bandwidth) and amplitude-related content (slope, slope-amp [slope divided by amplitude], and amplitude–spectrum area) were analyzed. Frequencies at 5 mins of ventricular fibrillation were altered in both acute myocardial infarction (p < .001 for all frequency characteristics) and postmyocardial infarction swine (p = .015 for mean, .002 for median, .002 for dominant frequency, and <.001 for bandwidth). At 5 mins, median frequency was highest in controls, 10.9 ± .4 Hz; lowest in acute myocardial infarction, 8.4 ± .5 Hz; and intermediate in postmyocardial infarction, 9.7 ± .5 Hz (p < .001 for acute myocardial infarction and p = .002 for postmyocardial infarction compared with control). Slope and amplitude–spectrum area were similar among the three groups with a shallow decline after minute 2, whereas slope-amp remained significantly altered for acute myocardial infarction swine at 5 mins (p = .003). Conclusions Ventricular fibrillation frequencies depend on myocardial substrate and evolve from the acute through healing phases of myocardial infarction. Amplitude related measures, however, are similar among these groups. It is unknown how defibrillation may be affected by relying on the ventricular fibrillation waveform without considering myocardial substrate. PMID:18552696

The effect of hyperthermia on the neuroepithelium of the 21-day guinea-pig foetus: histologic and ultrastructural study.

PubMed

Wanner, R A; Edwards, M J; Wright, R G

1976-04-01

Hyperthermia was induced in guinea-pigs on day 21 of gestation by placing them in an incubator set at 42-5 degrees-43-0 degrees C for 1 hr. At intervals thereafter foetuses were removed from the uterus and sections of the telencephalon were prepared for light and electron microscopy. The histologic and ultrastructural appearance of the telencephalon of the normal 21-day guinea-pig foetus was described for comparative purposes. Damage to cells in mitosis characterised by clumping of chromosomes, and dispersal of polysomes in interphase cells were observed immediately after hyperthermia. Breakdown of the network of junctional complexes was apparent at 4 hr and cellular proliferation was inhibited for 6-8 hr. Degenerative changes and cell deaths were observed deep in the venticular zone after 8 hr; the extent of cell death was related to the post-stressing temperature. Proliferation was resumed at 8 hr and damaged and dead cells moved outward toward the intermediate zone. Phagocytosis of debris by large mononuclear cells was a common finding. Cytoplasmic inclusions, some of which were Feulgen-positive, were present in otherwise normal ventricular cells. Occasional dead cells and empty spaces were present in the ventricular zone at 24 hr and by 48 hr the ventricular zone was normal in appearance. It was concluded that previously observed micrencephaly in the offspring of guine-pig mothers which were heat stressed on day 21 of gestation resulted from a temporary cessation of proliferation and partial depopulation of the proliferating neuroepithelium.

Internal medicine point-of-care ultrasound assessment of left ventricular function correlates with formal echocardiography.

PubMed

Johnson, Benjamin K; Tierney, David M; Rosborough, Terry K; Harris, Kevin M; Newell, Marc C

2016-02-01

Although focused cardiac ultrasonographic (FoCUS) examination has been evaluated in emergency departments and intensive care units with good correlation to formal echocardiography, accuracy for the assessment of left ventricular systolic function (LVSF) when performed by internal medicine physicians still needs independent evaluation. This prospective observational study in a 640-bed, academic, quaternary care center, included 178 inpatients examined by 10 internal medicine physicians who had completed our internal medicine bedside ultrasound training program. The ability to estimate LVSF with FoCUS as "normal," "mild to moderately decreased," or "severely decreased" was compared with left ventricular ejection fraction (>50%, 31-49%, and <31%, respectively) from formal echocardiography interpreted by a cardiologist. Sensitivity and specificity of FoCUS for any degree of LVSF impairment were 0.91 (95% confidence interval [CI] 0.80, 0.97) and 0.88 (95% CI 0.81, 0.93), respectively. The interrater agreement between internal medicine physician-performed FoCUS and formal echocardiography for any LVSF impairment was "good/substantial" with κ = 0.77 (p < 0.001), 95% CI (0.67, 0.87). Formal echocardiography was classified as "technically limited due to patient factors" in 20% of patients; however, echogenicity was sufficient in 100% of FoCUS exams to classify LVSF. Internal medicine physicians using FoCUS identify normal versus decreased LVSF with high sensitivity, specificity, and "good/substantial" interrater agreement when compared with formal echocardiography. These results support the role of cardiac FoCUS by properly trained internal medicine physicians for discriminating normal from reduced LVSF. © 2015 Wiley Periodicals, Inc.

Prevention of ventricular arrhythmia and calcium dysregulation in a catecholaminergic polymorphic ventricular tachycardia mouse model carrying calsequestrin-2 mutation.

PubMed

Alcalai, Ronny; Wakimoto, Hiroko; Arad, Michael; Planer, David; Konno, Tetsuo; Wang, Libin; Seidman, Jon G; Seidman, Christine E; Berul, Charles I

2011-03-01

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial arrhythmic syndrome caused by mutations in genes encoding the calcium-regulation proteins cardiac ryanodine receptor (RyR2) or calsequestrin-2 (CASQ2). Mechanistic studies indicate that CPVT is mediated by diastolic Ca(2+) overload and increased Ca(2+) leak through the RyR2 channel, implying that treatment targeting these defects might be efficacious in CPVT. CPVT mouse models that lack CASQ2 were treated with Ca(2+) -channel inhibitors, β-adrenergic inhibitors, or Mg(2+) . Treatment effects on ventricular arrhythmia, sarcoplasmic reticulum (SR) protein expression and Ca(2+) transients of isolated myocytes were assessed. Each study agent reduced the frequency of stress-induced ventricular arrhythmia in mutant mice. The Ca(2+) channel blocker verapamil was most efficacious and completely prevented arrhythmia in 85% of mice. Verapamil significantly increased the SR Ca(2+) content in mutant myocytes, diminished diastolic Ca(2+) overload, increased systolic Ca(2+) amplitude, and prevented Ca(2+) oscillations in stressed mutant myocytes. Ca(2+) channel inhibition by verapamil rectified abnormal calcium handling in CPVT myocytes and prevented ventricular arrhythmias. Verapamil-induced partial normalization of SR Ca(2+) content in mutant myocytes implicates CASQ2 as modulator of RyR2 activity, rather than or in addition to, Ca(2+) buffer protein. Agents such as verapamil that attenuate cardiomyocyte calcium overload are appropriate for assessing clinical efficacy in human CPVT. © 2010 Wiley Periodicals, Inc.

Prevention of Ventricular Arrhythmia and Calcium Dysregulation in a Catecholaminergic Polymorphic Ventricular Tachycardia Mouse Model Carrying Calsequestrin-2 Mutation

PubMed Central

Alcalai, Ronny; Wakimoto, Hiroko; Arad, Michael; Planer, David; Konno, Tetsuo; Wang, Libin; Seidman, Jon G.; Seidman, Christine E.; Berul, Charles I

2010-01-01

Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial arrhythmic syndrome caused by mutations in genes encoding the calcium-regulation proteins cardiac ryanodine receptor (RyR2) or calsequestrin-2 (CASQ2). Mechanistic studies indicate that CPVT is mediated by diastolic Ca2+ overload and increased Ca2+ leak through the RyR2 channel, implying that treatment targeting these defects might be efficacious in CPVT. Method and results CPVT mouse models that lack CASQ2 were treated with Ca2+-channel inhibitors, β-adrenergic inhibitors, or Mg2+. Treatment effects on ventricular arrhythmia, sarcoplasmic reticulum (SR) protein expression and Ca2+ transients of isolated myocytes were assessed. Each study agent reduced the frequency of stress-induced ventricular arrhythmia in mutant mice. The Ca2+ channel blocker verapamil was most efficacious and completely prevented arrhythmia in 85% of mice. Verapamil significantly increased the SR Ca2+ content in mutant myocytes, diminished diastolic Ca2+ overload, increased systolic Ca2+ amplitude, and prevented Ca2+ oscillations in stressed mutant myocytes. Conclusions Ca2+ channel inhibition by verapamil rectified abnormal calcium handling in CPVT myocytes and prevented ventricular arrhythmias. Verapamil-induced partial normalization of SR Ca2+ content in mutant myocytes implicates CASQ2 as modulator of RyR2 activity, rather than or in addition to, Ca2+ buffer protein. Agents such as verapamil that attenuate cardiomyocyte calcium overload are appropriate for assessing clinical efficacy in human CPVT. PMID:20807279

Nonlinear dynamics, fractals, cardiac physiology and sudden death

NASA Technical Reports Server (NTRS)

Goldberger, Ary L.

1987-01-01

The authors propose a diametrically opposite viewpoint to the generally accepted tendency of equating healthy function with order and disease with chaos. With regard to the question of sudden cardiac death and chaos, it is suggested that certain features of dynamical chaos related to fractal structure and fractal dynamics may be important organizing principles in normal physiology and that certain pathologies, including ventricular fibrillation, represent a class of 'pathological periodicities'. Some laboratory work bearing on the relation of nonlinear analysis to physiological and pathophysiological data is briefly reviewed, with tentative theories and models described in reference to the mechanism of ventricular fibrillation.

Echocardiographic measurements of left ventricular mass by a non-geometric method

NASA Technical Reports Server (NTRS)

Parra, Beatriz; Buckey, Jay; Degraff, David; Gaffney, F. Andrew; Blomqvist, C. Gunnar

1987-01-01

The accuracy of a new nongeometric method for calculating left ventricular myocardial volumes from two-dimensional echocardiographic images was assessed in vitro using 20 formalin-fixed normal human hearts. Serial oblique short-axis images were acquired from one point at 5-deg intervals, for a total of 10-12 cross sections. Echocardiographic myocardial volumes were calculated as the difference between the volumes defined by the epi- and endocardial surfaces. Actual myocardial volumes were determined by water displacement. Volumes ranged from 80 to 174 ml (mean 130.8 ml). Linear regression analysis demonstrated excellent agreement between the echocardiographic and direct measurements.

Modeling and control of a brushless DC axial flow ventricular assist device.

PubMed

Giridharan, Guruprasad A; Skliar, Mikhail; Olsen, Donald B; Pantalos, George M

2002-01-01

This article presents an integrated model of the human circulatory system that incorporates circulatory support by a brushless DC axial flow ventricular assist device (VAD), and a feedback VAD controller designed to maintain physiologically sufficient perfusion. The developed integrated model combines a network type model of the circulatory system with a nonlinear dynamic model of the brushless DC pump We show that maintaining a reference differential pressure between the left ventricle and aorta leads to adequate perfusion for different pathologic cases, ranging from normal heart to left heart asystole, and widely varying physical activity scenarios from rest to exercise.

Ventricular fibrillation associated with early repolarization in a patient with thyroid storm.

PubMed

Ueno, Akira; Yamamoto, Takeshi; Sato, Naoki; Tanaka, Keiji

2010-11-01

We present a case of a 69-year-old male who was hospitalized for the treatment of thyroid storm due to Grave's disease, who presented with unexpected ventricular fibrillation (VF). The possible etiology was early repolarization (ER), characterized by J-point elevation in inferior and posterolateral leads, unmasked by the attenuation of beta-adrenergic effect with normalization of thyroid hormones and following the administration of a beta-blocker. Our case focuses attention on the occurrence of VF in a patient with ER during the treatment of hyperthyroidism, which to our knowledge is the first such report.

Association between atrial fibrillation, atrial enlargement, and left ventricular geometric remodeling.

PubMed

Seko, Yuta; Kato, Takao; Haruna, Tetsuya; Izumi, Toshiaki; Miyamoto, Shoichi; Nakane, Eisaku; Inoko, Moriaki

2018-04-23

This study investigated the relationship between atrial fibrillation (AF) and left ventricular (LV) geometric patterns in a hospital-based population in Japan. We retrospectively analyzed 4444 patients who had undergone simultaneous scheduled transthoracic echocardiography (TTE) and electrocardiography during 2013. A total of 430 patients who had findings of previous myocardial infarctions (n = 419) and without the data on body surface area (n = 11) were excluded from the study. We calculated the LV mass index (LVMI) and relative wall (RWT) and categorized 4014 patients into four groups as follows: normal geometry (n = 3046); concentric remodeling (normal LVMI and high RWT, n = 437); concentric hypertrophy (high LVMI and high RWT, n = 149); and eccentric remodeling (high LVMI and normal RWT, n = 382). The mean left atrial volume indices (LAVI) were 22.5, 23.8, 33.3, and 37.0 mm/m 2 in patients with normal geometry, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy, respectively. The mean LV ejection fractions (LVEF) were 62.7, 62.6, 60.8, and 53.8%, respectively, whereas the prevalence of AF was 10.4%, 10.5%, 14.8%, and 16.8% in patients with normal geometry, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy, respectively. In conclusion, the prevalence of AF was increasing according to LV geometric remodeling patterns in association with LA size and LVEF.

Echocardiography parameters of clinically normal adult captive chimpanzees (Pan troglodytes).

PubMed

Sleeper, Meg M; Drobatz, Ken; Lee, D Richard; Lammey, Michael L

2014-04-15

To generate reference ranges for echocardiographic variables in clinically normal adult chimpanzees (Pan troglodytes). Retrospective cohort study. 88 clinically normal adult chimpanzees. Echocardiographic data obtained between 2002 and 2011 from chimpanzees at the Alamogordo Primate Facility were reviewed (263 echocardiograms obtained from 158 individuals). Data from clinically normal individuals (33 females and 55 males) were analyzed. Basic cardiac parameters measured in all individuals included aortic root diameter and left atrial diameter in the short and long axis during diastole. Left ventricular measurements included left ventricular internal diameter in systole and diastole and diastolic septal and posterior wall thickness. The E point to septal separation was also measured. Spectral Doppler measurements included the peak flow velocity of the pulmonary artery and aorta and diastolic transmitral flow. The presence of arrhythmias was also noted. Standard echocardiographic findings for a large group of adult female and male chimpanzees were obtained. Female and male chimpanzees were grouped by age in 10-year blocks, and echocardiographic findings were analyzed statistically by 10-year block. In male chimpanzees, cardiac arrhythmias were noted to increase with age. Cardiovascular disease is an important cause of morbidity and death in captive chimpanzees; however, basic echocardiographic measurements from a large cohort of clinically normal animals have not previously been reported. The number of animals in the present study was insufficient to generate reference ranges; however, data from a large cohort of clinically normal animals are presented. This information will be useful for veterinarians working in clinical and research settings with this species.

Extracellular Superoxide Dismutase Deficiency Exacerbates Pressure Overload–Induced Left Ventricular Hypertrophy and Dysfunction

PubMed Central

Lu, Zhongbing; Xu, Xin; Hu, Xinli; Zhu, Guangshuo; Zhang, Ping; van Deel, Elza D.; French, Joel P.; Fassett, John T.; Oury, Tim D.; Bache, Robert J.; Chen, Yingjie

2008-01-01

Extracellular superoxide dismutase (SOD) contributes only a small fraction to total SOD activity in the normal heart but is strategically located to scavenge free radicals in the extracellular compartment. To examine the physiological significance of extracellular SOD in the response of the heart to hemodynamic stress, we studied the effect of extracellular SOD deficiency on transverse aortic constriction (TAC)–induced left ventricular remodeling. Under unstressed conditions extracellular SOD deficiency had no effect on myocardial total SOD activity, the ratio of glutathione:glutathione disulfide, nitrotyrosine content, or superoxide anion production but resulted in small but significant increases in myocardial fibrosis and ventricular mass. In response to TAC for 6 weeks, extracellular SOD-deficient mice developed more severe left ventricular hypertrophy (heart weight increased 2.56-fold in extracellular SOD-deficient mice as compared with 1.99-fold in wild-type mice) and pulmonary congestion (lung weight increased 2.92-fold in extracellular SOD-deficient mice as compared with 1.84-fold in wild-type mice). Extracellular SOD-deficient mice also had more ventricular fibrosis, dilation, and a greater reduction of left ventricular fractional shortening and rate of pressure development after TAC. TAC resulted in greater increases of ventricular collagen I, collagen III, matrix metalloproteinase-2, matrix metalloproteinase-9, nitrotyrosine, and superoxide anion production. TAC also resulted in a greater decrease of the ratio of glutathione:glutathione disulfide in extracellular SOD-deficient mice. The finding that extracellular SOD deficiency had minimal impact on myocardial overall SOD activity but exacerbated TAC induced myocardial oxidative stress, hypertrophy, fibrosis, and dysfunction indicates that the distribution of extracellular SOD in the extracellular space is critically important in protecting the heart against pressure overload. PMID:17998475

Masked hypertension and cardiac remodeling in middle-aged endurance athletes.

PubMed

Trachsel, Lukas D; Carlen, Frederik; Brugger, Nicolas; Seiler, Christian; Wilhelm, Matthias

2015-06-01

Extensive endurance training and arterial hypertension are established risk factors for atrial fibrillation. We aimed to assess the proportion of masked hypertension in endurance athletes and the impact on cardiac remodeling, mechanics, and supraventricular tachycardias (SVT). Male participants of a 10-mile race were recruited and included if office blood pressure was normal (<140/90 mmHg). Athletes were stratified into a masked hypertension and normotension group by ambulatory blood pressure. Primary endpoint was diastolic function, expressed as peak early diastolic mitral annulus velocity (E'). Left ventricular global strain, left ventricular mass/volume ratio, left atrial volume index, signal-averaged P-wave duration (SAPWD), and SVT during 24-h Holter monitoring were recorded. From 108 runners recruited, 87 were included in the final analysis. Thirty-three (38%) had masked hypertension. The mean age was 42 ± 8 years. Groups did not differ with respect to age, body composition, cumulative training hours, and 10-mile race time. Athletes with masked hypertension had a lower E' and a higher left ventricular mass/volume ratio. Left ventricular global strain, left atrial volume index, SAPWD, and SVT showed no significant differences between the groups. In multiple linear regression analysis, masked hypertension was independently associated with E' (beta = -0.270, P = 0.004) and left ventricular mass/volume ratio (beta = 0.206, P = 0.049). Cumulative training hours was the only independent predictor for left atrial volume index (beta = 0.474, P < 0.001) and SAPWD (beta = 0.481, P < 0.001). In our study, a relevant proportion of middle-aged athletes had masked hypertension, associated with a lower diastolic function and a higher left ventricular mass/volume ratio, but unrelated to left ventricular systolic function, atrial remodeling, or SVT.

Elective correction of intracardiac lesions resulting from penetrating wounds of the heart.

PubMed Central

Morgan, S; Maturana, G; Urzua, J; Franck, R; Dubernet, J

1979-01-01

Controversy exists regarding the timing and technique of total correction of traumatic intracardiac lesions. Five patients with penetrating wounds of the heart received emergency treatment aimed at securing normal haemodynamics. No attempt was made to identify intracardiac lesions at this stage. Cineangiography two months to seven years later showed aorto-right ventricular fistulae in all patients, associated in two with aortic cusp laceration and in one with an aorto-left atrial fistula. The surgical approach for aorto-right ventricular fistula was through the right ventricle or aorta. Valvar injuries were treated by plastic reconstruction. All patients showed good clinical results when seen four to 11 years later. Traumatic intracardiac lesions in patients with stable haemodynamics after initial treatment should be operated on electively. The aortic approach is preferable for aorto-right ventricular fistulae. Conservative plastic repair of valvar injuries achieves long-term competence thus avoiding prosthetic replacement. PMID:505341

Increased release of brain serotonin reduces vulnerability to ventricular fibrillation in the cat

NASA Technical Reports Server (NTRS)

Lehnert, Hendrik; Lombardi, Federico; Raeder, Ernst A.; Lorenzo, Antonio V.; Verrier, Richard L.; Lown, Bernard; Wurtman, Richard J.

1987-01-01

The effect of administering the serotonin precursor 5-l-hydroxytryptophan, in conjunction with a monamine oxidase inhibitor phenelzine and a l-amino acid decarboxylase inhibitor carbidopa, on neurochemical changes in the concentrations of serotonin and 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid of the cat were investigated. Results showed that this drug regimen led to increases of serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in the cerebrospinal fluid by 330 and 830 percent, respectively. Concomitantly, the threshold of ventricular fibrillation was found to be elevated by 42 percent and the effective refractory period was prolonged by 7 percent; the efferent sympathetic neural activity was suppressed in the normal heart. The results indicate that the enhancement of central serotoninergic neurotransmission can reduce the susceptibility of the heart to ventricular fibrillation mediated through a decline in sympathetic neural traffic to the heart.

In vivo somatostatin, vasopressin, and oxytocin synthesis in diabetic rat hypothalamus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernstrom, J.D.; Fernstrom, M.H.; Kwok, R.P.

1990-04-01

The in vivo labeling of somatostatin-14, somatostatin-28, arginine vasopressin, and oxytocin was studied in rat hypothalamus after third ventricular administration of (35S)cysteine to streptozotocin-diabetic and normal rats. Immunoreactive somatostatin levels in hypothalamus were unaffected by diabetes, as was the incorporation of (35S)cysteine into hypothalamic somatostatin-14 and somatostatin-28. In contrast, immunoreactive vasopressin levels in hypothalamus and posterior pituitary (and oxytocin levels in posterior pituitary) were below normal in diabetic rats. Moreover, (35S)cysteine incorporation into hypothalamic vasopressin and oxytocin (probably mainly in the paraventricular nucleus because of its proximity to the third ventricular site of label injection) was significantly above normal. Themore » increments in vasopressin and oxytocin labeling were reversed by insulin administration. In vivo cysteine specific activity and the labeling of acid-precipitable protein did not differ between normal and diabetic animals; effects of diabetes on vasopressin and oxytocin labeling were therefore not caused by simple differences in cysteine specific activity. These results suggest that diabetes (1) does not influence the production of somatostatin peptides in hypothalamus but (2) stimulates the synthesis of vasopressin and oxytocin. For vasopressin at least, the increase in synthesis may be a compensatory response to the known increase in its secretion that occurs in uncontrolled diabetes.« less

An echocardiographic assessment of cardiac morphology and common ECG findings in teenage professional soccer players: reference ranges for use in screening

PubMed Central

Somauroo, J; Pyatt, J; Jackson, M; Perry, R; Ramsdale, D

2001-01-01

OBJECTIVE—To assess physiological cardiac adaptation in adolescent professional soccer players.
SUBJECTS AND DESIGN—Over a 32 month period 172 teenage soccer players were screened by echocardiography and ECG at a tertiary referral cardiothoracic centre. They were from six professional soccer teams in the north west of England, competing in the English Football League. One was excluded because of an atrial septal defect. The median age of the 171 players assessed was 16.7 years (5th to 95th centile range: 14-19) and median body surface area 1.68 m2 (1.39-2.06 m2).
MAIN OUTCOME MEASURES—Standard echocardiographic measurements were compared with predicted mean, lower, and upper limits in a cohort of normal controls after matching for age and surface area. Univariate regression analysis was used to assess the correlation between echocardiographic variables and the age and surface area of the soccer player cohort. ECG findings were also assessed.
RESULTS—All mean echocardiographic variables were greater than predicted for age and surface area matched controls (p < 0.001). All variables except left ventricular septal and posterior wall thickness showed a modest linear correlation with surface area (r = 0.2 to 0.4, p < 0.001); however, left ventricular mass was the only variable that was significantly correlated with age (r = 0.2, p < 0.01). Only six players (3.5%) had structural anomalies, none of which required further evaluation. All had normal left ventricular systolic function. Sinus bradycardia was found in 65 (39%). The Solokow-Lyon voltage criteria for left ventricular hypertrophy were present in 85 (50%) and the Romhilt-Estes points score (five or more) in 29 (17%). Repolarisation changes were present in 19 (11%), mainly in the inferior leads.
CONCLUSIONS—Chamber dimensions, left ventricular wall thickness and mass, and aortic root size were all greater than predicted for controls after matching for age and surface area. Sinus bradycardia and the ECG criteria for left ventricular hypertrophy were common but there was poor correlation with echocardiographic left ventricular hypertrophy. The type of hypertrophy found reflected the combined endurance and strength based training undertaken.


Keywords: cardiac morphology; professional soccer players; echocardiography; ECG findings PMID:11359746

Idiopathic normal-pressure hydrocephalus: temporal changes in ADC during cardiac cycle.

PubMed

Ohno, Naoki; Miyati, Tosiaki; Mase, Mitsuhito; Osawa, Tomoshi; Kan, Hirohito; Kasai, Harumasa; Hara, Masaki; Shibamoto, Yuta; Hayashi, Norio; Gabata, Toshifumi; Matsui, Osamu

2011-11-01

To determine whether temporal changes in apparent diffusion coefficient (ADC) over the cardiac cycle are different in patients with idiopathic normal-pressure hydrocephalus (INPH) as compared with patients with ex vacuo ventricular dilatation and healthy control subjects. This prospective study was approved by the institutional review board and was performed only after informed consent was obtained from each patient. At 1.5 T, electrocardiographically triggered single-shot diffusion echo-planar magnetic resonance imaging (b = 0 and 1000 sec/mm(2)) was performed with sensitivity encoding and half-scan techniques to minimize bulk motion. ΔADC was defined as the difference between maximum and minimum ADC on a pixel-by-pixel basis over 20 phases of the cardiac cycle. Mean ADC during the diastolic phase and ΔADC in the frontal white matter were determined in patients with INPH (n = 13), patients with ex vacuo ventricular dilatation (n = 8), and healthy volunteers (n = 10). Kruskal-Wallis tests were used to determine significance between groups. Mean ΔADC in the INPH group was significantly higher than that in the ex vacuo ventricular dilatation and control groups (P < .01 for both). There was no significant difference in ΔADC between the ex vacuo ventricular dilatation and control groups (P = .86). There was no significant difference in mean ADC during the diastolic phase among groups (P > .05 for all). There was no significant correlation between ΔADC and mean ADC during the diastolic phase in any group. Determination of fluctuation of ADC over the cardiac cycle may render it possible to noninvasively obtain new and more detailed information than that provided by standard ADC measurement in suspected INPH, potentially facilitating the diagnosis of this disease. RSNA, 2011

A novel ventricular restraint device (ASD) repetitively deliver Salvia miltiorrhiza to epicardium have good curative effects in heart failure management.

PubMed

Naveed, Muhammad; Wenhua, Li; Gang, Wang; Mohammad, Imran Shair; Abbas, Muhammad; Liao, Xiaoqian; Yang, Mengqi; Zhang, Li; Liu, Xiaolin; Qi, Xiaoming; Chen, Yineng; Jiadi, Lv; Ye, Linlan; Zhijie, Wang; Ding, Chen Ding; Feng, Yu; Xiaohui, Zhou

2017-11-01

A novel ventricular restraint is the non-transplant surgical option for the management of an end-stage dilated heart failure (HF). To expand the therapeutic techniques we design a novel ventricular restraint device (ASD) which has the ability to deliver a therapeutic drug directly to the heart. We deliver a Traditional Chinese Medicine (TCM) Salvia miltiorrhiza (Danshen Zhusheye) through active hydraulic ventricular support drug delivery system (ASD) and we hypothesize that it will show better results in HF management than the restraint device and drug alone. SD rats were selected and divided into five groups (n=6), Normal, HF, HF+SM (IV), HF+ASD, HF+ASD+SM groups respectively. Post myocardial infarction (MI), electrocardiography (ECG) showed abnormal heart function in all groups and HF+ASD+SM group showed a significant therapeutic improvement with respect to other treatment HF, HF+ASD, and HF+SM (IV) groups on day 30. The mechanical functions of the heart such as heart rate, LVEDP, and LVSP were brought to normal when treated with ASD+SM and show significant (P value<0.01) compared to other groups. BNP significantly declines in HF+ASD+SM group animals compared with other treatment groups. Masson's Trichrome staining was used to study histopathology of cardiac myocytes and quantification of fibrosis was assessed. The large blue fibrotic area was observed in HF, HF+ASD, and HF+SM (IV) groups while HF+ASD+SM showed negligible fibrotic myocyte at the end of study period (30days). This study proves that novel ASD device augments the therapeutic effect of the drug and delivers Salvia miltiorrhiza to the cardiomyocytes significantly as well as provides additional support to the dilated ventricle by the heart failure. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Effect of trimetazidine treatment on the transient outward potassium current of the left ventricular myocytes of rats with streptozotocin-induced type 1 diabetes mellitus.

PubMed

Xiang, Yu-luan; He, Li; Xiao, Jun; Xia, Shuang; Deng, Song-bai; Xiu, Yun; She, Qiang

2012-03-01

Cardiovascular complications are a leading cause of mortality in patients with diabetes mellitus (DM). The present study was designed to investigate the effects of trimetazidine (TMZ), an anti-angina drug, on transient outward potassium current (Ito) remodeling in ventricular myocytes and the plasma contents of free fatty acid (FFA) and glucose in DM. Sprague-Dawley rats, 8 weeks old and weighing 200-250 g, were randomly divided into three groups of 20 animals each. The control group was injected with vehicle (1 mM citrate buffer), the DM group was injected with 65 mg/kg streptozotocin (STZ) for induction of type 1 DM, and the DM + TMZ group was injected with the same dose of STZ followed by a 4-week treatment with TMZ (60 mg·kg-1·day-1). All animals were then euthanized and their hearts excised and subjected to electrophysiological measurements or gene expression analyses. TMZ exposure significantly reversed the increased plasma FFA level in diabetic rats, but failed to change the plasma glucose level. The amplitude of Ito was significantly decreased in left ventricular myocytes from diabetic rats relative to control animals (6.25 ± 1.45 vs 20.72 ± 2.93 pA/pF at +40 mV). The DM-associated Ito reduction was attenuated by TMZ. Moreover, TMZ treatment reversed the increased expression of the channel-forming alpha subunit Kv1.4 and the decreased expression of Kv4.2 and Kv4.3 in diabetic rat hearts. These data demonstrate that TMZ can normalize, or partially normalize, the increased plasma FFA content, the reduced Ito of ventricular myocytes, and the altered expression Kv1.4, Kv4.2, and Kv4.3 in type 1 DM.

Hypersensitivity myocarditis associated with ephedra use.

PubMed

Zaacks, S M; Klein, L; Tan, C D; Rodriguez, E R; Leikin, J B

1999-01-01

Ephedrine has previously been described as a causative factor of vasculitis but myocarditis has not yet been associated with either ephedrine or its plant derivative ephedra. A 39-year-old African American male with hypertension presented to Rush Presbyterian St. Luke's Medical Center with a 1-month history of progressive dyspnea on exertion, orthopnea, and dependent edema. He was taking Ma Huang (Herbalife) 1-3 tablets twice daily for 3 months along with other vitamin supplements, pravastatin, and furosemide. Physical examination revealed a male in mild respiratory distress. The lung fields had rales at both bases without audible wheezes. Internal jugular venous pulsations were 5 cm above the sternal notch. Medical therapy with intravenous furosemide and oral enalapril was initiated upon admission. Cardiac catheterization with coronary angiography revealed normal coronary arteries, a dilated left ventricle, moderate pulmonary hypertension, and a pulmonary capillary wedge pressure of 34 mm Hg. The patient had right ventricular biopsy performed demonstrating mild myocyte hypertrophy and an infiltrate consisting predominantly of lymphocytes with eosinophils present in significantly increased numbers. Treatment for myocarditis was initiated with azothioprine 200 mg daily and prednisone 60 mg per day with a tapering course over 6 months. Anticoagulation with warfarin and diuretics was initiated and angiotensin-converting enzyme inhibition was continued. Hydralazine was added later. One month into therapy, an echocardiogram demonstrated improved left ventricular function with only mild global hypokinesis. A repeat right ventricular biopsy 2 months after the first admission showed no evidence of myocarditis. At 6 months, left ventricular ejection fraction was normal (EFN 50%) and the patient asymptomatic. Ephedra (Ma Huang) is the suspected cause of hypersensitivity myocarditis in this patient due to the temporal course of disease and its propensity to induce vasculitis.

The Frank-Starling mechanism involves deceleration of cross-bridge kinetics and is preserved in failing human right ventricular myocardium.

PubMed

Milani-Nejad, Nima; Canan, Benjamin D; Elnakish, Mohammad T; Davis, Jonathan P; Chung, Jae-Hoon; Fedorov, Vadim V; Binkley, Philip F; Higgins, Robert S D; Kilic, Ahmet; Mohler, Peter J; Janssen, Paul M L

2015-12-15

Cross-bridge cycling rate is an important determinant of cardiac output, and its alteration can potentially contribute to reduced output in heart failure patients. Additionally, animal studies suggest that this rate can be regulated by muscle length. The purpose of this study was to investigate cross-bridge cycling rate and its regulation by muscle length under near-physiological conditions in intact right ventricular muscles of nonfailing and failing human hearts. We acquired freshly explanted nonfailing (n = 9) and failing (n = 10) human hearts. All experiments were performed on intact right ventricular cardiac trabeculae (n = 40) at physiological temperature and near the normal heart rate range. The failing myocardium showed the typical heart failure phenotype: a negative force-frequency relationship and β-adrenergic desensitization (P < 0.05), indicating the expected pathological myocardium in the right ventricles. We found that there exists a length-dependent regulation of cross-bridge cycling kinetics in human myocardium. Decreasing muscle length accelerated the rate of cross-bridge reattachment (ktr) in both nonfailing and failing myocardium (P < 0.05) equally; there were no major differences between nonfailing and failing myocardium at each respective length (P > 0.05), indicating that this regulatory mechanism is preserved in heart failure. Length-dependent assessment of twitch kinetics mirrored these findings; normalized dF/dt slowed down with increasing length of the muscle and was virtually identical in diseased tissue. This study shows for the first time that muscle length regulates cross-bridge kinetics in human myocardium under near-physiological conditions and that those kinetics are preserved in the right ventricular tissues of heart failure patients. Copyright © 2015 the American Physiological Society.

Relevance of water gymnastics in rehabilitation programs in patients with chronic heart failure or coronary artery disease with normal left ventricular function.

PubMed

Teffaha, Daline; Mourot, Laurent; Vernochet, Philippe; Ounissi, Fawzi; Regnard, Jacques; Monpère, Catherine; Dugué, Benoit

2011-08-01

Exercise training is included in cardiac rehabilitation programs to enhance physical capacity and cardiovascular function. Among the existing rehabilitation programs, exercises in water are increasingly prescribed. However, it has been questioned whether exercises in water are safe and relevant in patients with stable chronic heart failure (CHF), coronary artery disease (CAD) with normal systolic left ventricular function. The goal was to assess whether a rehabilitation program, including water-based gymnastic exercises, is safe and induces at least similar benefits as a traditional land-based training. Twenty-four male CAD patients and 24 male CHF patients with stable clinical status participated in a 3-week rehabilitation. They were randomized to either a group performing the training program totally on land (CADl, CHFl; endurance + callisthenic exercises) or partly in water (CADw, CHFw; land endurance + water callisthenic exercises). Before and after rehabilitation, left ventricular systolic and cardiorespiratory functions, hemodynamic variables and autonomic nervous activities were measured. No particular complications were associated with both of our programs. At rest, significant improvements were seen in CHF patients after both types of rehabilitation (increases in stroke volume and left ventricular ejection fraction [LVEF]) as well as a decrease in heart rate (HR) and in diastolic arterial pressure. Significant increases in peaks VO(2), HR, and power output were observed in all patients after rehabilitation in exercise test. The increase in LVEF at rest, in HR and power output at the exercise peak were slightly higher in CHFw than in CHFl. Altogether, both land and water-based programs were well tolerated and triggered improvements in cardiorespiratory function. Copyright © 2011 Elsevier Inc. All rights reserved.

Evaluation of effect of atorvastatin on left ventricular systolic function in rats with myocardial infarction via 2D-STI technique.

PubMed

Hua, Yan; Xie, Manying; Yin, Jiabao; Wang, Yu; Gan, Ling; Sang, Ming; Sun, Xiaodong; Li, Mingyang; Liu, Shanjun; Xu, Jinzhi

2018-05-01

This report aims to evaluate the effect of atorvastatin (Ator) on left ventricular systolic function in myocardial infarction (MI) rats. Forty healthy adult Sprague-Dawley rats were randomly divided into four groups: Ator group, MI group, sham-operation group and normal group. The left anterior descending coronary arteries were ligated to establish the MI model; after modeling, the Ator group was treated with Ator for 4 consecutive weeks. The echocardiographic detection was performed; the left ventricular myocardial systolic peak velocities, strain and strain rates were analyzed using the 2D-STI technique. After 4 weeks, myocardial tissues were taken from all rats and received the pathological examination. Left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) in Ator group and MI group were increased after operation, but left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were decreased; myocardial function were decreased significantly (p<0.05). After Ator treatment, myocardial function at the 3rd and 4th week after operation increased significantly (p<0.05). After Ator treatment, LVEDD and LVESD decreased while LVEF and LVFS increased in Ator group at the 3rd and 4th week after operation compared with MI group (p<0.05). At the 4th week after operation, LVEDD and LVESD in Ator group were decreased compared with those at the 1st and 2nd week after operation, but LVEF and LVFS were increased compared with those at the 1st, 2nd and 3rd week after operation (p<0.05). Pathological examination showed that necrosis and fibrosis of myocardial cells and inflammatory reaction were obvious in MI group. The inflammatory reaction of myocardial cells and myocardial fibrosis were lighter in Ator group. Ator can effectively improve the left ventricular systolic function in MI rats, which could be related to the reduction of response to inflammation and fibrosis.

Histopathological Correlates of Global and Segmental Left Ventricular Systolic Dysfunction in Experimental Chronic Chagas Cardiomyopathy.

PubMed

de Oliveira, Luciano Fonseca Lemos; Romano, Minna Moreira Dias; de Carvalho, Eduardo Elias Vieira; Cabeza, Jorge Mejia; Salgado, Hélio Cesar; Fazan Júnior, Rubens; Costa, Renata Sesti; da Silva, João Santana; Higuchi, Maria de Lourdes; Maciel, Benedito Carlos; Cunha-Neto, Edécio; Marin-Neto, José Antônio; Simões, Marcus Vinícius

2016-01-21

Chronic Chagas cardiomyopathy in humans is characterized by segmental left ventricular wall motion abnormalities (WMA), mainly in the early stages of disease. This study aimed at investigating the detection of WMA and its correlation with the underlying histopathological changes in a chronic Chagas cardiomyopathy model in hamsters. Female Syrian hamsters (n=34) infected with 3.5×10(4) or 10(5) blood trypomastigote Trypanosoma cruzi (Y strain) forms and an uninfected control group (n=7) were investigated. After 6 or 10 months after the infection, the animals were submitted to in vivo evaluation of global and segmental left ventricular systolic function by echocardiography, followed by euthanasia and histological analysis for quantitative assessment of fibrosis and inflammation with tissue sampling in locations coinciding with the left ventricular wall segmentation employed at the in vivo echocardiographic evaluation. Ten of the 34 infected animals (29%) showed reduced left ventricular ejection fraction (<73%). Left ventricular ejection fraction was more negatively correlated with the intensity of inflammation (r=-0.63; P<0.0001) than with the extent of fibrosis (r=-0.36; P=0.036). Among the 24 animals with preserved left ventricular ejection fraction (82.9±5.5%), 8 (33%) showed segmental WMA predominating in the apical, inferior, and posterolateral segments. The segments exhibiting WMA, in comparison to those with normal wall motion, showed a greater extent of fibrosis (9.3±5.7% and 7±6.3%, P<0.0001) and an even greater intensity of inflammation (218.0±111.6 and 124.5±84.8 nuclei/mm², P<0.0001). Isolated WMA with preserved global systolic left ventricular function is frequently found in Syrian hamsters with experimental chronic Chagas cardiomyopathy whose underlying histopathological features are mainly inflammatory. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Impact of Hypertension on Ventricular-Arterial Coupling and Regional Myocardial Work at Rest and during Isometric Exercise

PubMed Central

Kuznetsova, Tatiana; D’hooge, Jan; Kloch-Badelek, Malgorzata; Sakiewicz, Wojciech; Thijs, Lutgarde; Staessen, Jan A.

2013-01-01

Background To understand better the mechanism of left ventricular (LV) remodeling related to hypertension, it is important to evaluate LV function in relation to the changes in loading conditions. The aim of this study was to investigate changes in conventional ventricular-arterial coupling indexes, LV strain, and a new index reflecting regional myocardial work assessed noninvasively at rest and during isometric exercise in a random sample including participants with normal blood pressure and those with hypertension. Methods A total of 148 participants (53.4% women; mean age, 52.0 years; 39.2% with hypertension) underwent simultaneous echocardiographic and arterial data acquisition at rest and during increased afterload (handgrip exercise). End-systolic pressure was determined from the carotid pulse wave. Arterial elastance (Ea) and LV elastance (Ees) were calculated as end-systolic pressure/stroke volume and end-systolic pressure/end-systolic volume. Doppler tissue imaging and two-dimensional speckle tracking were used to derive LV longitudinal strain. Regional myocardial work (ejection work density [EWD]) was the area of the pressure-strain loop during ejection. Results At rest, with adjustments applied, Ees (3.06 vs 3.71 mmHg/mL,P = .0003), Ea/Ees (0.54 vs 0.47,P=.002) and EWD (670 vs 802 Pa/m2, P = .0001) differed significantly between participants with normal blood pressure and those with hypertension. During handgrip exercise, Ea and Ea/Ees significantly increased (P < .0001) in both groups. Doppler tissue imaging and two-dimensional LV strain decreased in participants with hypertension (P ≤ .008). Only in subjects with normal blood pressure EWD significantly increased (+14.7%, P = .0009). Conclusions Although patients with hypertension compared with those with normal blood pressure have increased LV systolic stiffness and regional myocardial work to match arterial load at rest, they might have diminished cardiac reserve to increase myocardial performance, as estimated by EWD during isometric exercise. PMID:22622108

Alterations in left ventricular curvature and principal strains in dilated cardiomyopathy with functional mitral regurgitation.

PubMed

Tibayan, Frederick A; Lai, David T M; Timek, Tomasz A; Dagum, Paul; Liang, David; Zasio, Mary K; Daughters, George T; Miller, D Craig; Ingels, Neil B

2003-05-01

Functional mitral regurgitation (FMR) is increasingly recognized as a left ventricular (LV) disease. Dilated cardiomyopathy (DCM) is commonly accompanied by FMR and reduction of LV torsion. Therapeutic targets for DCM include LV size reduction, altered LV shape, elimination of MR, and increasing LV torsion. It was hypothesized that, in addition to increasing LV size, DCM with FMR would alter normal LV shape and reduce and alter the direction of principal strains across the LV wall. This hypothesis was tested by measuring changes in epicardial and endocardial 2-D principal strains and regional radii of curvature accompanying tachycardia-induced cardiomyopathy in ovine hearts. Radio-opaque marker arrays were implanted into the left ventricle of eight sheep, including one subepicardial triangle and one subendocardial triangle in the anterior wall of the left ventricle. At one week postoperatively, biplane videofluoroscopy was used to determine marker dynamics. Rapid ventricular pacing was then instituted until FMR and signs of heart failure developed, and fluoroscopy was repeated. Circumferential LV radii of curvature were determined from marker triplets. DCM changed the normal epicardial oval LV cross-section to a more circular configuration. The endocardium maintained its normal circular shape as the left ventricle dilated. Deformations of the triangles from end-diastole to end-systole were determined, and the magnitude and direction of 2-D principal strains calculated. DCM was associated with decreased magnitude of both epicardial (-0.095 +/- 0.055 versus -0.040 +/- 0.032, p = 0.006) and endocardial (-0.117 +/- 0.047 versus -0.073 +/- 0.037, p = 0.023) principal strains. DCM reduced the angle of epicardial but not endocardial principal strain. DCM with FMR is associated with LV dilation, circularization of the normally oval equatorial circumferential LV epicardium, transmural reduction in principal strain, and decrease in angle of principal epicardial strain. These changes contribute to a reduction in the net torsional moment and may guide the development of reverse remodeling procedures for the dilated, failing ventricle with FMR.

Left atrial enlargement increases the risk of major adverse cardiac events independent of coronary vasodilator capacity.

PubMed

Koh, Angela S; Murthy, Venkatesh L; Sitek, Arkadiusz; Gayed, Peter; Bruyere, John; Wu, Justina; Di Carli, Marcelo F; Dorbala, Sharmila

2015-09-01

Longstanding uncontrolled atherogenic risk factors may contribute to left atrial (LA) hypertension, LA enlargement (LAE) and coronary vascular dysfunction. Together they may better identify risk of major adverse cardiac events (MACE). The aim of this study was to test the hypothesis that chronic LA hypertension as assessed by LAE modifies the relationship between coronary vascular function and MACE. In 508 unselected subjects with a normal clinical (82)Rb PET/CT, ejection fraction ≥40 %, no prior coronary artery disease, valve disease or atrial fibrillation, LAE was determined based on LA volumes estimated from the hybrid perfusion and CT transmission scan images and indexed to body surface area. Absolute myocardial blood flow and global coronary flow reserve (CFR) were calculated. Subjects were systematically followed-up for the primary end-point - MACE - a composite of all-cause death, myocardial infarction, hospitalization for heart failure, stroke, coronary artery disease progression or revascularization. During a median follow-up of 862 days, 65 of the subjects experienced a composite event. Compared with subjects with normal LA size, subjects with LAE showed significantly lower CFR (2.25 ± 0.83 vs. 1.95 ± 0.80, p = 0.01). LAE independently and incrementally predicted MACE even after accounting for clinical risk factors, medication use, stress left ventricular ejection fraction, stress left ventricular end-diastolic volume index and CFR (chi-squared statistic increased from 30.9 to 48.3; p = 0.001). Among subjects with normal CFR, those with LAE had significantly worse event-free survival (risk adjusted HR 5.4, 95 % CI 2.3 - 12.8, p < 0.0001). LAE and reduced CFR are related but distinct cardiovascular adaptations to atherogenic risk factors. LAE is a risk marker for MACE independent of clinical factors and left ventricular volumes; individuals with LAE may be at risk of MACE despite normal coronary vascular function.

Normal pressure hydrocephalus in patients with myelomeningocele.

PubMed

Hammock, M K; Milhorat, T H; Baron, I S

1976-01-01

Although the syndrome of normal pressure hydrocephalus (NPH) was described in the adult as early as 1964, it has only recently been recognized in the child. In this preliminary report, eight myelomeningocele patients with presumed NPH were evaluated before and after ventricular shunting procedures. Cranial computed tomography and serial psychological testing have proved to be particularly valuable both in the pre-operative and post-operative assessment of these patients and have the distinct advantage of being simple, non-invasive diagnostic measures. Continuous intra-ventricular pressure monitoring has shown what promises to be characteristic elevated pressure plateaux imposed on normal baseline cerebrospinal fluid (CSF) pressures in so-called NPH but is a more difficult clinical procedure, necessarily associated with potential complications. Although decreasing response to growth-stimulating hormone can be demonstrated in patients with long-standing hydrocephalus, this endocrine malfunction cannot be considered an early indicator of intracranial pathology. Single IQ scores are inadequate measures of intellectural function in children with NPH and serial examinations should be carried out. Detailed neuropsychological testing will document performance IQ scores well below verbal IQ scores and will generally show failure of psychomotor development to keep pace with chronological ageing. Initial studies indicate that improved performance scores can be expected within 1 1/2 to 3 months following successful ventricular shunting operations, and that any downward trend in pre-operative test scoring can at least be reversed. Statistically significant improvements in full-scale IQ scores have not been seen, however, before the end of the first post-operative year. Clinically, improved attentiveness and sociability, and decreased spasticity (if present prior to surgery) can be expected following shunting. Over-all, ventriculomegaly, normal CSF pressure, stable head size, and non-progressive neurological symptoms cannot be regarded as sufficient criteria for the diagnosis of an arrested state of hydrocephalus, and should suggest NPH, especially in those children who demonstrate a discrepancy between performance and verbal IQ scores and who fail to exhibit continuing psychomotor development with advancing age.

Left ventricular diastolic filling with an implantable ventricular assist device: beat to beat variability with overall improvement

NASA Technical Reports Server (NTRS)

Nakatani, S.; Thomas, J. D.; Vandervoort, P. M.; Zhou, J.; Greenberg, N. L.; Savage, R. M.; McCarthy, P. M.

1997-01-01

OBJECTIVES: We studied the effects of left ventricular (LV) unloading by an implantable ventricular assist device on LV diastolic filling. BACKGROUND: Although many investigators have reported reliable systemic and peripheral circulatory support with implantable LV assist devices, little is known about their effect on cardiac performance. METHODS: Peak velocities of early diastolic filling, late diastolic filling, late to early filling ratio, deceleration time of early filling, diastolic filling period and atrial filling fraction were measured by intraoperative transesophageal Doppler echocardiography before and after insertion of an LV assist device in eight patients. A numerical model was developed to simulate this situation. RESULTS: Before device insertion, all patients showed either a restrictive or a monophasic transmitral flow pattern. After device insertion, transmitral flow showed rapid beat to beat variation in each patient, from abnormal relaxation to restrictive patterns. However, when the average values obtained from 10 consecutive beats were considered, overall filling was significantly normalized from baseline, with early filling velocity falling from 87 +/- 31 to 64 +/- 26 cm/s (p < 0.01) and late filling velocity rising from 8 +/- 11 to 32 +/- 23 cm/s (p < 0.05), resulting in an increase in the late to early filling ratio from 0.13 +/- 0.18 to 0.59 +/- 0.38 (p < 0.01) and a rise in the atrial filling fraction from 8 +/- 10% to 26 +/- 17% (p < 0.01). The deceleration time (from 112 +/- 40 to 160 +/- 44 ms, p < 0.05) and the filling period corrected by the RR interval (from 39 +/- 8% to 54 +/- 10%, p < 0.005) were also significantly prolonged. In the computer model, asynchronous LV assistance produced significant beat to beat variation in filling indexes, but overall a normalization of deceleration time as well as other variables. CONCLUSIONS: With LV assistance, transmitral flow showed rapidly varying patterns beat by beat in each patient, but overall diastolic filling tended to normalize with an increase of atrial contribution to the filling. Because of the variable nature of the transmitral flow pattern with the assist device, the timing of the device cycle must be considered when inferring diastolic function from transmitral flow pattern.

Quantitative analysis of the Ca2+ -dependent regulation of delayed rectifier K+ current IKs in rabbit ventricular myocytes.

PubMed

Bartos, Daniel C; Morotti, Stefano; Ginsburg, Kenneth S; Grandi, Eleonora; Bers, Donald M

2017-04-01

[Ca 2+ ] i enhanced rabbit ventricular slowly activating delayed rectifier K + current (I Ks ) by negatively shifting the voltage dependence of activation and slowing deactivation, similar to perfusion of isoproterenol. Rabbit ventricular rapidly activating delayed rectifier K + current (I Kr ) amplitude and voltage dependence were unaffected by high [Ca 2+ ] i . When measuring or simulating I Ks during an action potential, I Ks was not different during a physiological Ca 2+ transient or when [Ca 2+ ] i was buffered to 500 nm. The slowly activating delayed rectifier K + current (I Ks ) contributes to repolarization of the cardiac action potential (AP). Intracellular Ca 2+ ([Ca 2+ ] i ) and β-adrenergic receptor (β-AR) stimulation modulate I Ks amplitude and kinetics, but details of these important I Ks regulators and their interaction are limited. We assessed the [Ca 2+ ] i dependence of I Ks in steady-state conditions and with dynamically changing membrane potential and [Ca 2+ ] i during an AP. I Ks was recorded from freshly isolated rabbit ventricular myocytes using whole-cell patch clamp. With intracellular pipette solutions that controlled free [Ca 2+ ] i , we found that raising [Ca 2+ ] i from 100 to 600 nm produced similar increases in I Ks as did β-AR activation, and the effects appeared additive. Both β-AR activation and high [Ca 2+ ] i increased maximally activated tail I Ks , negatively shifted the voltage dependence of activation, and slowed deactivation kinetics. These data informed changes in our well-established mathematical model of the rabbit myocyte. In both AP-clamp experiments and simulations, I Ks recorded during a normal physiological Ca 2+ transient was similar to I Ks measured with [Ca 2+ ] i clamped at 500-600 nm. Thus, our study provides novel quantitative data as to how physiological [Ca 2+ ] i regulates I Ks amplitude and kinetics during the normal rabbit AP. Our results suggest that micromolar [Ca 2+ ] i , in the submembrane or junctional cleft space, is not required to maximize [Ca 2+ ] i -dependent I Ks activation during normal Ca 2+ transients. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Quantitative analysis of the Ca2+‐dependent regulation of delayed rectifier K+ current I Ks in rabbit ventricular myocytes

PubMed Central

Bartos, Daniel C.; Morotti, Stefano; Ginsburg, Kenneth S.; Grandi, Eleonora

2017-01-01

Key points [Ca2+]i enhanced rabbit ventricular slowly activating delayed rectifier K+ current (I Ks) by negatively shifting the voltage dependence of activation and slowing deactivation, similar to perfusion of isoproterenol.Rabbit ventricular rapidly activating delayed rectifier K+ current (I Kr) amplitude and voltage dependence were unaffected by high [Ca2+]i.When measuring or simulating I Ks during an action potential, I Ks was not different during a physiological Ca2+ transient or when [Ca2+]i was buffered to 500 nm. Abstract The slowly activating delayed rectifier K+ current (I Ks) contributes to repolarization of the cardiac action potential (AP). Intracellular Ca2+ ([Ca2+]i) and β‐adrenergic receptor (β‐AR) stimulation modulate I Ks amplitude and kinetics, but details of these important I Ks regulators and their interaction are limited. We assessed the [Ca2+]i dependence of I Ks in steady‐state conditions and with dynamically changing membrane potential and [Ca2+]i during an AP. I Ks was recorded from freshly isolated rabbit ventricular myocytes using whole‐cell patch clamp. With intracellular pipette solutions that controlled free [Ca2+]i, we found that raising [Ca2+]i from 100 to 600 nm produced similar increases in I Ks as did β‐AR activation, and the effects appeared additive. Both β‐AR activation and high [Ca2+]i increased maximally activated tail I Ks, negatively shifted the voltage dependence of activation, and slowed deactivation kinetics. These data informed changes in our well‐established mathematical model of the rabbit myocyte. In both AP‐clamp experiments and simulations, I Ks recorded during a normal physiological Ca2+ transient was similar to I Ks measured with [Ca2+]i clamped at 500–600 nm. Thus, our study provides novel quantitative data as to how physiological [Ca2+]i regulates I Ks amplitude and kinetics during the normal rabbit AP. Our results suggest that micromolar [Ca2+]i, in the submembrane or junctional cleft space, is not required to maximize [Ca2+]i‐dependent I Ks activation during normal Ca2+ transients. PMID:28008618

The paradox of left ventricular assist device unloading and myocardial recovery in end-stage dilated cardiomyopathy: implications for heart failure in the elderly.

PubMed

Butler, Craig R; Jugdutt, Bodh I

2012-09-01

Dilated cardiomyopathy (DCM) is a common debilitating condition with limited therapeutic options besides heart transplantation or palliation. It is characterized by maladaptive remodeling of cardiomyocytes, extracellular collagen matrix (ECCM) and left ventricular (LV) geometry which contributes to further dysfunction. LV assist devices (LVADs) can reverse adverse remodeling in end-stage DCM. However, there is a disconnect between the benefits of prolonged unloading with LVAD at molecular and cellular levels and the low rate of bridge to recovery (BTR). Potential explanations for this paradox include insufficient reverse ECCM remodeling and/or excessive reverse cardiomyocyte remodeling with atrophy. LVAD therapy is associated with decreased collagen turnover and cross-linking and increased tissue angiotensin II (AngII), whereas LVAD combined with angiotensin-converting enzyme inhibition results in decreased tissue AngII and collagen cross-linking, normalizes LV end-diastolic pressure volume relationships and is associated with modestly higher rates of BTR. Much remains to be learned about ventricular reverse remodeling after LVAD. This can be facilitated through systematic collection and comparison of recovered and unrecovered myocardium. Importantly, vigilant monitoring for ventricular recovery among LVAD patients is needed, particularly in older patients receiving LVAD for destination therapy. In addition, prospective multicenter trials are needed to clarify the potential benefit of concomitant heart failure therapy with selective β2 agonism on ventricular recovery.

Independent effects of both right and left ventricular function on plasma brain natriuretic peptide.

PubMed

Vogelsang, Thomas Wiis; Jensen, Ruben J; Monrad, Astrid L; Russ, Kaspar; Olesen, Uffe H; Hesse, Birger; Kjaer, Andreas

2007-09-01

Brain natriuretic peptide (BNP) is increased in heart failure; however, the relative contribution of the right and left ventricles is largely unknown. To investigate if right ventricular function has an independent influence on plasma BNP concentration. Right (RVEF), left ventricular ejection fraction (LVEF), and left ventricular end-diastolic volume index (LVEDVI) were determined in 105 consecutive patients by first-pass radionuclide ventriculography (FP-RNV) and multiple ECG-gated equilibrium radionuclide ventriculography (ERNV), respectively. BNP was analyzed by immunoassay. Mean LVEF was 0.51 (range 0.10-0.83) with 36% having a reduced LVEF (<0.50). Mean RVEF was 0.50 (range 0.26-0.78) with 43% having a reduced RVEF (<0.50). The mean LVEDVI was 92 ml/m2 with 22% above the upper normal limit (117 ml/m2). Mean BNP was 239 pg/ml range (0.63-2523). In univariate linear regression analysis LVEF, LVEDVI and RVEF all correlated significantly with log BNP (p<0.0001). In a multivariate analysis only RVEF and LVEF remained significant. The parameter estimates of the final adjusted model indicated that RVEF and LVEF influence on log BNP were of the same magnitude. BNP, which is a strong prognostic marker in heart failure, independently depends on both left and right ventricular systolic function. This might, at least in part, explain why BNP holds stronger prognostic value than LVEF alone.

Reference values of left heart echocardiographic dimensions and mass in male peri-pubertal athletes.

PubMed

Cavarretta, Elena; Maffessanti, Francesco; Sperandii, Fabio; Guerra, Emanuele; Quaranta, Federico; Nigro, Antonia; Minati, Monia; Rebecchi, Marco; Fossati, Chiara; Calò, Leonardo; Pigozzi, Fabio

2018-01-01

Background Several articles have proposed reference values in healthy paediatric subjects, but none of them has evaluated a large population of healthy trained adolescents. Design The study purpose was to establish normal echocardiographic measurements of left heart (aortic root, left atrium and left ventricular dimensions and mass) in relation to age, weight, height, body mass index, body surface area and training hours in this specific population. Methods We retrospectively evaluated 2151 consecutive, healthy, peri-pubertal athletes (100% male, mean age 12.4 ± 1.4 years, range 8-18) referred to a single centre for pre-participation screening. All participants were young soccer athletes who trained for a mean of 7.2 ± 1.1 h per week. Results Left ventricular internal diameters, wall thickness, left ventricular mass, aortic root and left atrium diameters were significantly correlated to age, body surface area, height and weight ( p < 0.01). Age, height, weight and body surface area were found associated with chamber size, while body mass index and training hours were not. Inclusion of both age and body size parameters in the statistical models resulted in improved overall explained variance for diameters and left ventricular mass. Conclusion Equations, mean values and percentile charts for the different age groups may be useful as reference data in efficiently assessing left ventricular parameters in young athletes.

Capecitabine-induced ventricular fibrillation arrest: Possible Kounis syndrome.

PubMed

Kido, Kazuhiko; Adams, Val R; Morehead, Richard S; Flannery, Alexander H

2016-04-01

We report the case of capecitabine-induced ventricular fibrillation arrest, possibly secondary to type I Kounis syndrome. A 47-year-old man with a history of T3N1 moderately differentiated adenocarcinoma of the colon, status-post sigmoid resection, was started on adjuvant capecitabine approximately five months prior to presentation of cardiac arrest secondary to ventricular fibrillation. An electrocardiogram (EKG) revealed ST segment elevation on the lateral leads and the patient was taken emergently to the cardiac catheterization laboratory. The catheterization revealed no angiographically significant stenosis and coronary artery disease was ruled out. After ruling out other causes of cardiac arrest, the working diagnosis was capecitabine-induced ventricular fibrillation arrest. As such, an inflammatory work up was sent to evaluate for the possibility of a capecitabine hypersensitivity, or Kounis syndrome, and is the first documented report in the literature to do so when evaluating Kounis syndrome. Immunoglobulin E (IgE), tryptase, and C-reactive protein were normal but histamine, interleukin (IL)-6, and IL-10 were elevated. Histamine elevation supports the suspicion that our patient had type I Kounis syndrome. Naranjo adverse drug reaction probability scale indicates a probable adverse effect due to capecitabine with seven points. A case of capecitabine-induced ventricular fibrillation arrest is reported, with a potential for type 1 Kounis syndrome as an underlying pathology supported by immunologic work up. © The Author(s) 2014.

Left ventricular assist device and drug therapy for the reversal of heart failure.

PubMed

Birks, Emma J; Tansley, Patrick D; Hardy, James; George, Robert S; Bowles, Christopher T; Burke, Margaret; Banner, Nicholas R; Khaghani, Asghar; Yacoub, Magdi H

2006-11-02

In patients with severe heart failure, prolonged unloading of the myocardium with the use of a left ventricular assist device has been reported to lead to myocardial recovery in small numbers of patients for varying periods of time. Increasing the frequency and durability of myocardial recovery could reduce or postpone the need for subsequent heart transplantation. We enrolled 15 patients with severe heart failure due to nonischemic cardiomyopathy and with no histologic evidence of active myocarditis. All had markedly reduced cardiac output and were receiving inotropes. The patients underwent implantation of left ventricular assist devices and were treated with lisinopril, carvedilol, spironolactone, and losartan to enhance reverse remodeling. Once regression of left ventricular enlargement had been achieved, the beta2-adrenergic-receptor agonist clenbuterol was administered to prevent myocardial atrophy. Eleven of the 15 patients had sufficient myocardial recovery to undergo explantation of the left ventricular assist device a mean (+/-SD) of 320+/-186 days after implantation of the device. One patient died of intractable arrhythmias 24 hours after explantation; another died of carcinoma of the lung 27 months after explantation. The cumulative rate of freedom from recurrent heart failure among the surviving patients was 100% and 88.9% 1 and 4 years after explantation, respectively. The quality of life as assessed by the Minnesota Living with Heart Failure Questionnaire score at 3 years was nearly normal. Fifty-nine months after explantation, the mean left ventricular ejection fraction was 64+/-12%, the mean left ventricular end-diastolic diameter was 59.4+/-12.1 mm, the mean left ventricular end-systolic diameter was 42.5+/-13.2 mm, and the mean maximal oxygen uptake with exercise was 26.3+/-6.0 ml per kilogram of body weight per minute. In this single-center study, we found that sustained reversal of severe heart failure secondary to nonischemic cardiomyopathy could be achieved in selected patients with the use of a left ventricular assist device and a specific pharmacologic regimen. Copyright 2006 Massachusetts Medical Society.

Left ventricular geometric patterns in end-stage kidney disease: Determinants and course over time.

PubMed

Nubé, Menso J; Hoekstra, Tiny; Doganer, Volkan; Bots, Michiel L; Blankestijn, Peter J; van den Dorpel, Marinus; Kamp, Otto; Ter Wee, Piet M; de Roij van Zuijdewijn, Camiel L M; Grooteman, Muriel P C

2018-02-20

While concentric left ventricular hypertrophy (cLVH) predominates in non-dialysis-dependent chronic kidney disease (CKD), eccentric left ventricular hypertrophy (eLVH) is most prevalent in dialysis-dependent CKD stage 5 (CKD5D). In these patients, the risk of sudden death is 5× higher than in individuals with cLVH. Currently, it is unknown which factors determine left ventricular (LV) geometry and how it changes over time in CKD5D. Data from participants of the CONvective TRAnsport Study who underwent serial transthoracic echocardiography were used. Based on left ventricular mass (LVM) and relative wall thickness (RWT), 4 types of left ventricular geometry were distinguished: normal, concentric remodeling, eLVH, and cLVH. Determinants of eLVH were assessed with logistic regression. Left ventricular geometry of patients who died and survived were compared. Long-term changes in RWT and LVM were evaluated with a linear mixed model. Three hundred twenty-two patients (63.1 ± 13.3 years) were included. At baseline, LVH was present in 71% (cLVH: 27%; eLVH: 44%). Prior cardiovascular disease (CVD) was positively associated with eLVH and ß-blocker use inversely. None of the putative volume parameters showed any relationship with eLVH. Although eLVH was most prevalent in non-survivors, the distribution of left ventricular geometry did not vary over time. The finding that previous CVD was positively associated with eLVH may result from the permanent high cardiac output and the strong tendency for aortic valve calcification in this group of long-term hemodialysis patients, who suffer generally also from chronic anemia and various other metabolic derangements. No association was found between eLVH and parameters of fluid balance. The distribution of left ventricular geometry did not alter over time. The assumption that LV geometry worsens over time in susceptible individuals, who then suffer from a high risk of dying, may explain these findings. © 2018 The Authors Hemodialysis International published by Wiley Periodicals, Inc. on behalf of International Society for Hemodialysis.

Regression equations for calculation of z scores for echocardiographic measurements of left heart structures in healthy Han Chinese children.

PubMed

Wang, Shan-Shan; Hong, Wen-Jing; Zhang, Yu-Qi; Chen, Shu-Bao; Huang, Guo-Ying; Zhang, Hong-Yan; Chen, Li-Jun; Wu, Lan-Ping; Shen, Rong; Liu, Yi-Qing; Zhu, Jun-Xue

2018-06-01

Clinical decision making in children with heart disease relies on detailed measurements of cardiac structures using two-dimensional and M-mode echocardiography. However, no echocardiographic reference values are available for the Chinese children. We aimed to establish z-score regression equations for left heart structures in a population-based cohort of healthy Chinese Han children. Echocardiography was performed in 545 children with a normal heart. The dimensions of the aortic valve annulus (AVA), aortic sinuses of Valsalva (ASV), sinotubular junction (STJ), ascending aorta (AAO), left atrium (LA), mitral valve annulus (MVA), interventricular septal end-diastolic thickness (IVSd), interventricular septal end-systolic thickness (IVSs), left ventricular end-diastolic diameter (LVIDd), left ventricular end-systolic diameter (LVIDs), left ventricular posterior wall end-diastolic thickness (LVPWd), left ventricular posterior wall end-systolic thickness (LVPWs) were measured. Regression analyses were conducted to relate the measurements of left heart structures to body surface area (BSA). Left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were calculated. Several models were used, and the adjusted R2 values were compared for each model. AVA, ASV, STJ, AAO, LA, MVA, IVSd, IVSs, LVIDd, LVIDs, LVPWd, and LVPWs had a cubic relationship with BSA. LVEF and LVFS fell within a narrow range. Our results provide reference values for z scores and regression equations for left heart structures in Han Chinese children. These data may help make a quick and accurate judgment of the routine clinical measurement of left heart structures in children with heart disease. © 2018 Wiley Periodicals, Inc.

Electrocardiographic Left Ventricular Hypertrophy as a Predictor of Cardiovascular Disease Independent of Left Ventricular Anatomy in Persons ≥ 65 Years of Age

PubMed Central

Leigh, J. Adam; O’Neal, Wesley T.; Soliman, Elsayed Z.

2016-01-01

Left ventricular hypertrophy (LVH) diagnosed by electrocardiography (ECG-LVH) and echocardiography (echo-LVH) are independently associated with an increased risk of cardiovascular disease (CVD) events. However, it is unknown if ECG-LVH retains its predictive properties independent of left ventricular anatomy. We compared the risk of CVD associated with ECG-LVH and echo-LVH in 4,076 participants (41% male, 86% white) from the Cardiovascular Health Study (CHS), who were free of baseline CVD. ECG-LVH was defined with Minnesota ECG Classification criteria from baseline ECG data. Echo-LVH was defined by sex-specific left ventricular mass values normalized to body surface area (male: >102 g/m2; female: >88 g/m2). ECG-LVH was detected in 144 (3.5%) participants and echo-LVH in 430 (11%) participants. Over a median follow-up of 10.6 years, 2,274 CVD events occurred. In a multivariable Cox regression analysis adjusted for common CVD risk factors, ECG-LVH (HR=1.84, 95%CI=1.51, 2.24) and echo-LVH (HR=1.35, 95%CI=1.19, 1.54) were associated with an increased risk for CVD events. The association between ECG-LVH and CVD events was not substantively altered with further adjustment for echo-LVH (HR=1.76, 95%CI=1.45, 2.15). In conclusion, the association of ECG-LVH with CVD events is not dependent on echo-LVH. This finding provides support to the concept that ECG-LVH is an electrophysiologic marker with predictive properties independent of left ventricular anatomy. PMID:27067620

Dyssynchronous ventricular contraction in Wolff-Parkinson-White syndrome: a risk factor for the development of dilated cardiomyopathy.

PubMed

Dai, Chen-Cheng; Guo, Bao-Jing; Li, Wen-Xiu; Xiao, Yan-Yan; Jin, Mei; Han, Lin; Sun, Jing-Ping; Yu, Cheuk-Man; Dong, Jian-Zeng

2013-11-01

Emerging evidence suggests that significant left ventricular dysfunction may arise in right-sided septal or paraseptal accessory pathways (APs) with Wolff-Parkinson-White syndrome, even in the absence of recurrent or incessant tachycardia. During 1 year and 9 months, we identified four consecutive female children with median age of 8 years diagnosed as having dilated cardiomyopathy (DCM) combined with overt right-sided APs several years ago. Incessant or recurrent tachycardia as the cause of DCM could be excluded. Anti-heart failure chemotherapy did not produce satisfactory effects. The patients underwent radiofrequency ablations (RFCAs). This report describes the clinical and echocardiographic characteristics of the cases before and after the ablation. Dyssynchronous ventricular contraction was observed in all patients. The locations of the APs were the right-sided anteroseptum and the free wall (n = 2 each). All patients received successful RFCAs. Their physical activities and growth improved greatly, and the echocardiographic data demonstrated that their left ventricular (LV) contraction recovered to synchrony shortly after the ablation and that their LV function recovered to normal gradually during the follow-up. A causal relationship between overt ventricular preexcitation and the development of DCM is supported by the complete recovery of LV function and reversed LV remodeling after the loss of ventricular preexcitation. Preexcitation-related dyssynchrony was probably the crucial mechanism. Not only right-sided septal or paraseptal but also free wall overt APs may induce LV dysfunction and even DCM. AP-induced DCM is an indication for ablation with a good prognosis.

Value of the Qrs-T Angle in Predicting the Induction of Ventricular Tachyarrhythmias in Patients with Chagas Disease.

PubMed

Zampa, Hugo Bizetto; Moreira, Dalmo Ar; Ferreira Filho, Carlos Alberto Brandão; Souza, Charles Rios; Menezes, Camila Caldas; Hirata, Henrique Seichii; Armaganijan, Luciana Vidal

2014-10-28

Background: The QRS-T angle correlates with prognosis in patients with heart failure and coronary artery disease, reflected by an increase in mortality proportional to an increase in the difference between the axes of the QRS complex and T wave in the frontal plane. The value of this correlation in patients with Chagas heart disease is currently unknown. Objective: Determine the correlation of the QRS-T angle and the risk of induction of ventricular tachycardia / ventricular fibrillation (VT / VF) during electrophysiological study (EPS) in patients with Chagas disease. Methods: Case-control study at a tertiary center. Patients without induction of VT / VF on EPS were used as controls. The QRS-T angle was categorized as normal (0-105º), borderline (105-135º) or abnormal (135-180º). Differences between groups for continuous variables were analyzed with the t test or Mann-Whitney test, and for categorical variables with Fisher's exact test. P values < 0.05 were considered significant. Results: Of 116 patients undergoing EPS, 37.9% were excluded due to incomplete information / inactive records or due to the impossibility to correctly calculate the QRS-T angle (presence of left bundle branch block and atrial fibrillation). Of 72 patients included in the study, 31 induced VT / VF on EPS. Of these, the QRS-T angle was normal in 41.9%, borderline in 12.9% and abnormal in 45.2%. Among patients without induction of VT / VF on EPS, the QRS-T angle was normal in 63.4%, borderline in 14.6% and abnormal in 17.1% (p = 0.04). When compared with patients with normal QRS-T angle, those with abnormal angle had a fourfold higher risk of inducing ventricular tachycardia / ventricular fibrillation on EPS [odds ratio (OR) 4; confidence interval (CI) 1.298-12.325; p = 0.028]. After adjustment for other variables such as age, ejection fraction (EF) and QRS size, there was a trend for the abnormal QRS-T angle to identify patients with increased risk of inducing VT / VF during EPS (OR 3.95; CI 0.99-15.82; p = 0.052). The EF also emerged as a predictor of induction of VT / VF: for each point increase in EF, there was a 4% reduction in the rate of sustained ventricular arrhythmia on EPS. Conclusions: Changes in the QRS-T angle and decreases in EF were associated with an increased risk of induction of VT / VF on EPS.Fundamento: O ângulo QRS-T mostra correlação com prognóstico em pacientes com insuficiência cardíaca e doença coronariana, traduzido por um aumento na mortalidade proporcional ao aumento na diferença entre os eixos do complexo QRS e da onda T no plano frontal. Até hoje, nenhuma informação a este respeito foi obtida em pacientes com cardiopatia chagásica. Objetivo: Correlacionar o ângulo QRS-T com a indução de taquicardia ventricular / fibrilação ventricular (TV / FV) em chagásicos durante estudo eletrofisiológico (EEF). Métodos: Estudo caso-controle em centro terciário. Pacientes sem indução de TV / FV ao EEF foram utilizados como controles. O ângulo QRS-T foi categorizado como normal (0-105º), limítrofe (105-135º) e anormal (135-180º). As diferenças entre os grupos foram analisadas pelo teste t ou teste de Mann-Whitney para variáveis contínuas, e teste exato de Fisher ou qui-quadrado para variáveis categóricas. Valores de p < 0,05 foram considerados significativos. Resultados: De 116 pacientes submetidos ao EEF, 37,9% foram excluídos por estarem com dados incompletos / prontuários inativos ou pela impossibilidade de se calcular corretamente o ângulo QRS-T (presença de bloqueio de ramo esquerdo e fibrilação atrial). De 72 pacientes incluídos, 31 induziram TV / FV ao EEF. Destes, o ângulo QRS-T se encontrava normal em 41,9%, limítrofe em 12,9% e anormal em 45,2%. No grupo de pacientes sem indução de TV / FV, o ângulo QRS-T se encontrava normal em 63,4%, limítrofe em 14,6% e anormal em 17,1% (p = 0,04). Quando comparados aos pacientes com ângulo QRS-T normal, o risco de indução de TV / FV nos pacientes com ângulo anormal foi quatro vezes maior [odds ratio (OR) 4; intervalo de confiança (IC) 1,298-12,325; p = 0,028). Após ajuste para outras variáveis como idade, fração de ejeção (FE) e tamanho do QRS, houve tendência do ângulo QRS-T anormal em identificar pacientes com maior risco de indução de TV / FV (OR 3,95; IC 0,99-15,82; p = 0,052). A FE também se evidenciou como preditora de indução de TV / FV: um ponto de aumento na FE reduziu em 4% a taxa de indução de arritmia ventricular sustentada ao EEF. Conclusões: Alterações no ângulo QRS-T e redução na FE estiveram associadas a um aumento no risco de indução de TV / FV ao EEF.

Echocardiographic findings in stable outpatients with properly functioning HeartMate II left ventricular assist devices.

PubMed

Topilsky, Yan; Oh, Jae K; Atchison, Fawn W; Shah, Dipesh K; Bichara, Valentina M; Schirger, John A; Kushwaha, Sudhir S; Pereira, Naveen L; Park, Soon J

2011-02-01

Continuous-flow left ventricular assist devices (LVADs) have become part of the standard of care for the treatment of advanced heart failure. However, knowledge of normal values for transthoracic echocardiographic examination and measurements in these patients are lacking. All transthoracic echocardiographic examinations in 63 consecutive patients, performed 90 and 180 days after surgery with the implantation of a HeartMate II continuous-flow LVAD between February 2007 and January 2010, were retrospectively analyzed. All patients had to be outpatients at 3 and 6 months after surgery and considered stable on LVAD therapy (New York Heart Association class I or II and no need for inotropes, intravenous furosemide, or hospitalization). End-diastolic and end-systolic diameters and left ventricular mass decreased considerably compared with baseline measurements before LVAD implantation. Mitral inflow deceleration time increased (188 ± 70 vs 132.5 ± 27 msec, P = .009) and left atrial volume (84.1 ± 33 vs 141.7 ± 62 mL, P = .003) and E/e' ratio decreased (20.3 ± 9 vs 26 ± 11, P = .01), all consistent with decreased left ventricular filling pressure. Estimated right ventricular (RV) and right atrial pressure decreased significantly (34.1 ± 10 vs 51.7 ± 14 mm Hg and 9.5 ± 5 vs 14.4 ± 5 mm Hg, respectively, P < .0001 for both). Quantitatively estimated RV function (P = .02), RV fractional area change (27.9 ± 10% vs 37.4 ± 10.9%, P < .0001), and the RV index of myocardial performance (0.32 ± 0.1 vs 0.65 ± 0.2 vs 0.32 ± .01, P < .0001) improved, suggesting improved RV efficiency. LVAD therapy resulted in significant decreases in the severity of mitral regurgitation. Tricuspid regurgitation improved in patients who had concurrent tricuspid surgical correction and was unchanged otherwise. Aortic regurgitation severity increased 3 months after LVAD implantation. There were no significant differences in any of the echocardiographic parameters in the 6-month evaluation compared with the 3-month evaluation. This is the first report of selected typical echocardiographic values in a group of stable patients with normally functioning HeartMate II continuous-flow LVADs. A stable functioning continuous LVAD is associated with evidence of efficient unloading of the left ventricle, improved RV function, significant improvement in mitral regurgitation, improvement in tricuspid regurgitation only in patients undergoing repair, and increased aortic regurgitation. These normal data provide a basis for future echocardiographic studies after LVAD implantation. Copyright © 2011 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Recovery from exercise at varying work loads - Time course of responses of heart rate and systolic intervals

NASA Technical Reports Server (NTRS)

Nandi, P. S.; Spodick, D. H.

1977-01-01

The time course of the recovery period was characterized by noninvasive measurements after 4 minute bicycle exercise at 3 separate work loads in volunteers with normal peak responses. Most responses started immediately to return toward resting control values. Left ventricular ejection time and stroke volume change are discussed. Changes in pre-ejection period were determined by changes in isovolume contraction time, and factors affecting the degree and rate of return are considered. The rates of change in the ejection time index and in the ratio pre-ejection period/left ventricular ejection time were virtually independent of load throughout most of recovery.

Left ventricular dyssynchrony in patients with normal ventricular systolic function referred for exercise echocardiography.

PubMed

Bernheim, Alain M; Nakajima, Yoshie; Pellikka, Patricia A

2008-10-01

Exercise testing is often normal despite the presence of exertional symptoms. We hypothesized that left ventricular (LV) dyssynchrony might occur in some patients in the absence of ischemia, LV dysfunction, or wide QRS, and might contribute to exertional symptoms and diminished exercise capacity. Echocardiographic parameters were assessed before and with exercise in 40 patients (age 62 +/- 8 years, 27 with exertional symptoms). All had normal clinically indicated exercise echocardiograms and narrow QRS. The time to peak systolic velocity (Ts) was measured in 12 segments to calculate the standard deviation (Ts-SD) and the maximal difference (Ts-diff). At rest, 25 patients (63%) had dyssynchrony by Ts-SD. With exercise, mean Ts-SD did not increase significantly (34.9 +/- 19.3 ms vs 39.5 +/- 27.2 ms, P = .28). However, Ts-SD increased by greater than 40% in 15 patients (37.5%), remained stable in 19 patients (47.5%), and decreased by greater than 40% in 6 patients (15%). Similar responses were observed for Ts-diff. Patients with exercise-induced dyssynchrony were not more likely to have symptoms. Exercise capacity was inversely correlated with resting Ts-SD (r = -0.37, P = .02) and resting Ts-diff (r = -0.38, P = .02), but not with exercise-induced changes in dyssynchrony. Patients with resting dyssynchrony had higher resting heart rate (73 +/- 12 vs 63 +/- 11 beats/min, P = .02). LV dyssynchrony may occur more frequently than previously thought and may develop with exercise in the absence of ischemia. Exercise-induced LV dyssynchrony was not related to exertional symptoms or exercise capacity. Patients with dyssynchrony at rest had a higher resting heart rate and achieved a lower workload; this may indicate early myocardial impairment.

Symptom-limited exercise testing causes sustained diastolic dysfunction in patients with coronary disease and low effort tolerance.

PubMed

Fragasso, G; Benti, R; Sciammarella, M; Rossetti, E; Savi, A; Gerundini, P; Chierchia, S L

1991-05-01

Exercise stress testing is routinely used for the noninvasive assessment of coronary artery disease and is considered a safe procedure. However, the provocation of severe ischemia might potentially cause delayed recovery of myocardial function. To investigate the possibility that maximal exercise testing could induce prolonged impairment of left ventricular function, 15 patients with angiographically proved coronary disease and 9 age-matched control subjects with atypical chest pain and normal coronary arteries were studied. Radionuclide ventriculography was performed at rest, at peak exercise, during recovery and 2 and 7 days after exercise. Ejection fraction, peak filling and peak emptying rates and left ventricular wall motion were analyzed. All control subjects had a normal exercise test at maximal work loads and improved left ventricular function on exercise. Patients developed 1 mm ST depression at 217 +/- 161 s at a work load of 70 +/- 30 W and a rate-pressure product of 18,530 +/- 4,465 mm Hg x beats/min. Although exercise was discontinued when angina or equivalent symptoms occurred, in all patients diagnostic ST depression (greater than or equal to 1 mm) developed much earlier than symptoms. Predictably, at peak exercise patients showed a decrease in ejection fraction and peak emptying and filling rates. Ejection fraction and peak emptying rate normalized within the recovery period, whereas peak filling rate remained depressed throughout recovery (p less than 0.002) and was still reduced 2 days after exercise (p less than 0.02). In conclusion, in patients with severe impairement of coronary flow reserve, maximal exercise may cause sustained impairement of diastolic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Normative biometry of the fetal brain using magnetic resonance imaging.

PubMed

Kyriakopoulou, Vanessa; Vatansever, Deniz; Davidson, Alice; Patkee, Prachi; Elkommos, Samia; Chew, Andrew; Martinez-Biarge, Miriam; Hagberg, Bibbi; Damodaram, Mellisa; Allsop, Joanna; Fox, Matt; Hajnal, Joseph V; Rutherford, Mary A

2017-07-01

The fetal brain shows accelerated growth in the latter half of gestation, and these changes can be captured by 2D and 3D biometry measurements. The aim of this study was to quantify brain growth in normal fetuses using Magnetic Resonance Imaging (MRI) and to produce reference biometry data and a freely available centile calculator ( https://www.developingbrain.co.uk/fetalcentiles/ ). A total of 127 MRI examinations (1.5 T) of fetuses with a normal brain appearance (21-38 gestational weeks) were included in this study. 2D and 3D biometric parameters were measured from slice-to-volume reconstructed images, including 3D measurements of supratentorial brain tissue, lateral ventricles, cortex, cerebellum and extra-cerebral CSF and 2D measurements of brain biparietal diameter and fronto-occipital length, skull biparietal diameter and occipitofrontal diameter, head circumference, transverse cerebellar diameter, extra-cerebral CSF, ventricular atrial diameter, and vermis height, width, and area. Centiles were constructed for each measurement. All participants were invited for developmental follow-up. All 2D and 3D measurements, except for atrial diameter, showed a significant positive correlation with gestational age. There was a sex effect on left and total lateral ventricular volumes and the degree of ventricular asymmetry. The 5th, 50th, and 95th centiles and a centile calculator were produced. Developmental follow-up was available for 73.1% of cases [mean chronological age 27.4 (±10.2) months]. We present normative reference charts for fetal brain MRI biometry at 21-38 gestational weeks. Developing growth trajectories will aid in the better understanding of normal fetal brain growth and subsequently of deviations from typical development in high-risk pregnancies or following premature delivery.

Clinical significance of fragmented QRS complexes or J waves in patients with idiopathic ventricular arrhythmias.

PubMed

Seong, Choong Sil; Gwag, Hye Bin; Hwang, Jin Kyung; Park, Seung Jung; Park, Kyoung-Min; Kim, June Soo; On, Young Keun

2018-01-01

Idiopathic ventricular fibrillation (IVF) can cause sudden cardiac death. Previous studies have reported that J waves and fragmented QRS complexes (f-QRS) are arrhythmogenic markers and predictors of cardiac events. We evaluated the prevalence and clinical significance of J waves and f-QRS in patients with IVF. We studied 81 patients who received an implantable cardioverter defibrillator (ICD) due to IVF between October 1999 and June 2015. We assessed the prevalence of J waves and f-QRS using electrocardiograms (ECGs). Patients were classified into three groups: J wave group (n = 35), f-QRS group (n = 20), or normal ECG group (n = 26). The control group included 81 subjects without heart disease who were matched for age, sex, and race. We compared syncope, sudden cardiac arrest, and appropriate ICD shock between the three groups. The follow-up duration was 4.1 years. J waves and f-QRS were more frequent in patients with IVF than in control subjects (43.2%, 21% vs. 24.7%, 19.7%, P < 0.001). Out of the three groups, clinical cardiac events were most frequent in the f-QRS group (50% vs. 45.7% vs. 11.5%, P = 0.028). A comparison of the combined group of J wave and f-QRS versus the normal ECG group revealed that the combined group had a higher frequency of clinical cardiac events than the normal ECG group (47.3% vs. 11.5%, respectively, P = 0.009). Patients with IVF had higher prevalence of f-QRS or J waves. And patients with f-QRS or J waves were at higher risk of recurrent ventricular fibrillation.

Idiopathic dilated cardiomyopathy: computerized anatomic study of relashionship between septal and free left ventricle wall.

PubMed

Juliani, Paulo Sérgio; Costa, Eder França da; Correia, Aristides Tadeu; Monteiro, Rosangela; Jatene, Fabio Biscegli

2014-01-01

A feature of dilated cardiomyopathy is the deformation of ventricular cavity, which contributes to systolic dysfunction. Few studies have evaluated this deformation bearing in mind ventricular regions and segments of the ventricle, which could reveal important details of the remodeling process, supporting a better understanding of its role in functional impairment and the development of new therapeutic strategies. To evaluate if, in basal, equatorial and apical regions, increased internal transverse perimeter of left ventricle in idiopathic dilated cardiomyopathy occurs proportionally between the septal and non-septal segment. We performed an anatomical study with 28 adult hearts from human cadavers. One group consisted of 18 hearts with idiopathic dilated cardiomyopathy and another group with 10 normal hearts. After lamination and left ventricle digital image capture, in three different regions (base, equator and apex), the transversal internal perimeter of left ventricle was divided into two segments: septal and not septal. These segments were measured by proper software. It was established an index of proportionality between these segments, called septal and non-septal segment index. Then we determined whether this index was the same in both groups. Among patients with normal hearts and idiopathic dilated cardiomyopathy, the index of proportionality between the two segments (septal and non-septal) showed no significant difference in the three regions analyzed. The comparison results of the indices NSS/SS among normal and enlarged hearts were respectively: in base 1.99 versus 1.86 (P=0.46), in equator 2.22 versus 2.18 (P=0.79) and in apex 2.96 versus 3.56 (P=0.11). In the idiopathic dilated cardiomyopathy, the transversal dilatation of left ventricular internal perimeter occurs proportionally between the segments corresponding to the septum and free wall at the basal, equatorial and apical regions of this chamber.

Notch signalling in cardiovasculogenesis: insight into their role in early cardiovascular development.

PubMed

Saravanakumar, Marimuthu; Devaraj, Halagowder

2013-05-01

The role of Notch signalling in congenital cardiovascular disease is evident by the identification of human mutations in several Notch signalling components, which also indicates the importance of activated Notch pathway in cardiovascular biology. Therefore, the aim of the present study is to investigate the expression pattern of the components of Notch signalling molecules and their role in mice embryonic heart and vascular development. Group A: normal control pregnant mice, group B: pregnant mice were injected with DMSO, group C: DAPT were subcutaneously injected to pregnant mice. The morphological and molecular changes of trabeculation-defective phenotype were analysed using histological, scanning electron microscope, immunoblot, immunolocalization and reverse transcriptase-PCR. E15.5 DAPT-treated mice revealed that there was a major reduction in the formation of septal walls between the ventricular chambers compared with normal control pregnant mice. VEGF expression was found in the DAPT treated and wild-type embryonic artery, whereas notch target genes GATA4, Hey1 expression were not found in the DAPT treated mice embryo. The role of Notch in ventricular development is supported by the trabeculation-defective phenotype seen in standard and endocardial-specific inhibition of Notch targets. The present study reveals the significant role of Notch signalling during the formation of ventricular septum and proper development of endothelial cell lineage and its precursor in mice cardiogenesis.

Modelling the heart with the atrioventricular plane as a piston unit.

PubMed

Maksuti, Elira; Bjällmark, Anna; Broomé, Michael

2015-01-01

Medical imaging and clinical studies have proven that the heart pumps by means of minor outer volume changes and back-and-forth longitudinal movements in the atrioventricular (AV) region. The magnitude of AV-plane displacement has also shown to be a reliable index for diagnosis of heart failure. Despite this, AV-plane displacement is usually omitted from cardiovascular modelling. We present a lumped-parameter cardiac model in which the heart is described as a displacement pump with the AV plane functioning as a piston unit (AV piston). This unit is constructed of different upper and lower areas analogous with the difference in the atrial and ventricular cross-sections. The model output reproduces normal physiology, with a left ventricular pressure in the range of 8-130 mmHg, an atrial pressure of approximatly 9 mmHg, and an arterial pressure change between 75 mmHg and 130 mmHg. In addition, the model reproduces the direction of the main systolic and diastolic movements of the AV piston with realistic velocity magnitude (∼10 cm/s). Moreover, changes in the simulated systolic ventricular-contraction force influence diastolic filling, emphasizing the coupling between cardiac systolic and diastolic functions. The agreement between the simulation and normal physiology highlights the importance of myocardial longitudinal movements and of atrioventricular interactions in cardiac pumping. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Delayed Onset of Atrial Fibrillation and Ventricular Tachycardia after an Automobile Lightning Strike.

PubMed

Drigalla, Dorian; Essler, Shannon E; Stone, C Keith

2017-11-01

Lightning strike is a rare medical emergency. The primary cause of death in lightning strike victims is immediate cardiac arrest. The mortality rate from lightning exposure can be as high as 30%, with up to 70% of patients left with significant morbidity. An 86-year-old male was struck by lightning while driving his vehicle and crashed. On initial emergency medical services evaluation, he was asymptomatic with normal vital signs. During his transport, he lost consciousness several times and was found to be in atrial fibrillation with intermittent runs of ventricular tachycardia during the unconscious periods. In the emergency department, atrial fibrillation persisted and he experienced additional episodes of ventricular tachycardia. He was treated with i.v. amiodarone and admitted to cardiovascular intensive care unit, where he converted to a normal sinus rhythm on the amiodarone drip. He was discharged home without rhythm-control medications and did not have further episodes of dysrhythmias on follow-up visits. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Lightning strikes are one of the most common injuries suffered from natural phenomenon, and short-term mortality ordinarily depends on the cardiac effects. This case demonstrates that the cardiac effects can be multiple, delayed, and recurrent, which compels the emergency physician to be vigilant in the initial evaluation and ongoing observation of patients with lightning injuries. Copyright © 2017 Elsevier Inc. All rights reserved.

Investigating structural brain changes of dehydration using voxel-based morphometry.

PubMed

Streitbürger, Daniel-Paolo; Möller, Harald E; Tittgemeyer, Marc; Hund-Georgiadis, Margret; Schroeter, Matthias L; Mueller, Karsten

2012-01-01

Dehydration can affect the volume of brain structures, which might imply a confound in volumetric and morphometric studies of normal or diseased brain. Six young, healthy volunteers were repeatedly investigated using three-dimensional T(1)-weighted magnetic resonance imaging during states of normal hydration, hyperhydration, and dehydration to assess volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). The datasets were analyzed using voxel-based morphometry (VBM), a widely used voxel-wise statistical analysis tool, FreeSurfer, a fully automated volumetric segmentation measure, and SIENAr a longitudinal brain-change detection algorithm. A significant decrease of GM and WM volume associated with dehydration was found in various brain regions, most prominently, in temporal and sub-gyral parietal areas, in the left inferior orbito-frontal region, and in the extra-nuclear region. Moreover, we found consistent increases in CSF, that is, an expansion of the ventricular system affecting both lateral ventricles, the third, and the fourth ventricle. Similar degrees of shrinkage in WM volume and increase of the ventricular system have been reported in studies of mild cognitive impairment or Alzheimer's disease during disease progression. Based on these findings, a potential confound in GM and WM or ventricular volume studies due to the subjects' hydration state cannot be excluded and should be appropriately addressed in morphometric studies of the brain.

Investigating Structural Brain Changes of Dehydration Using Voxel-Based Morphometry

PubMed Central

Streitbürger, Daniel-Paolo; Möller, Harald E.; Tittgemeyer, Marc; Hund-Georgiadis, Margret; Schroeter, Matthias L.; Mueller, Karsten

2012-01-01

Dehydration can affect the volume of brain structures, which might imply a confound in volumetric and morphometric studies of normal or diseased brain. Six young, healthy volunteers were repeatedly investigated using three-dimensional T 1-weighted magnetic resonance imaging during states of normal hydration, hyperhydration, and dehydration to assess volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). The datasets were analyzed using voxel-based morphometry (VBM), a widely used voxel-wise statistical analysis tool, FreeSurfer, a fully automated volumetric segmentation measure, and SIENAr a longitudinal brain-change detection algorithm. A significant decrease of GM and WM volume associated with dehydration was found in various brain regions, most prominently, in temporal and sub-gyral parietal areas, in the left inferior orbito-frontal region, and in the extra-nuclear region. Moreover, we found consistent increases in CSF, that is, an expansion of the ventricular system affecting both lateral ventricles, the third, and the fourth ventricle. Similar degrees of shrinkage in WM volume and increase of the ventricular system have been reported in studies of mild cognitive impairment or Alzheime s disease during disease progression. Based on these findings, a potential confound in GM and WM or ventricular volume studies due to the subjects’ hydration state cannot be excluded and should be appropriately addressed in morphometric studies of the brain. PMID:22952926

Determination of left ventricular mass by echocardiography in normotensive diabetic patients.

PubMed

Hirayama, H; Sugano, M; Abe, N; Yonemochi, H; Makino, N

2000-12-01

Patients with Type 2 diabetes mellitus (DM) have excessive cardiovascular morbidity and mortality, even in the absence of hypertension. Left ventricular hypertrophy (LVH), which is an ominous prognostic sign and an independent risk factor for cardiac events, is often present in Type 2 DM patients. Forty-two Type 2 DM patients without hypertension, all of whom had been diagnosed more than 10 years ago, were examined in the present study. They had no evidence of renal dysfunction and had not received any anti-hypertensive drugs. Age-matched healthy normal subjects (n=47) were recruited as controls. All participants were classified according to the left ventricular mass index (LVMI) using M-mode echocardiography and their systolic function (fractional shortening) was examined. The systolic function was not significantly different between the Type 2 DM and control groups. LVH can be seen even in the normotensive Type 2 DM patients, with these patients still having a higher LVMI than the normal control subjects. Although the plasma insulin levels were not significantly increased in the Type 2 DM patients, the LVMI significantly correlated with plasma insulin levels. However, the LVMI did not significantly correlate with plasma fasting glucose and hemoglobin A1c in the Type 2 DM patients. These results suggest that LVH in Type 2 DM patients without hypertension may be associated with elevated plasma insulin levels.

An Electromechanical Left Ventricular Wedge Model to Study the Effects of Deformation on Repolarization during Heart Failure

PubMed Central

Rocha, B. M.; Toledo, E. M.; Barra, L. P. S.; dos Santos, R. Weber

2015-01-01

Heart failure is a major and costly problem in public health, which, in certain cases, may lead to death. The failing heart undergo a series of electrical and structural changes that provide the underlying basis for disturbances like arrhythmias. Computer models of coupled electrical and mechanical activities of the heart can be used to advance our understanding of the complex feedback mechanisms involved. In this context, there is a lack of studies that consider heart failure remodeling using strongly coupled electromechanics. We present a strongly coupled electromechanical model to study the effects of deformation on a human left ventricle wedge considering normal and hypertrophic heart failure conditions. We demonstrate through a series of simulations that when a strongly coupled electromechanical model is used, deformation results in the thickening of the ventricular wall that in turn increases transmural dispersion of repolarization. These effects were analyzed in both normal and failing heart conditions. We also present transmural electrograms obtained from these simulations. Our results suggest that the waveform of electrograms, particularly the T-wave, is influenced by cardiac contraction on both normal and pathological conditions. PMID:26550570

["Normal pressure" hydrocephalus].

PubMed

Philippon, Jacques

2005-03-01

Normal pressure hydrocephalus (NPH) or, more precisely, chronic adult hydrocephalus, is a complex condition. Even if the basic mechanism is found in an impediment to CSF absorption, the underlying pathology is heterogeneous. In secondary NPH, the disruption of normal CSF pathways, following meningitis or sub-arachnoid haemorrhage, is responsible for ventricular dilatation. However, in about half of the cases, the etiology remains obscure. NPH is more frequently found in elderly people, probably in relation with the increased incidence of cerebrovascular disease. The diagnosis of NPH is based upon a triad of clinical symptoms. The main symptom is gait disturbances, followed by urinary incontinence and various degree of cognitive changes. The latter two symptoms are not prerequisites for the diagnosis. Radiological ventricular dilatation without cortical sulcal enlargement is a key factor, as well as substantial clinical improvement after CSF withdrawal (CSF tap test). Other CSF dynamic studies and various imaging investigations have been proposed to improve diagnostic accuracy, but no simple test can predict the results of CSF drainage. The current treatment is ventriculo-peritonial shunting, ideally using an adjustable valve. Results are directly dependent upon the accuracy of the preoperative diagnosis. Post-surgical complications may be observed in about 10% of cases.

Normal Ranges of Right Ventricular Systolic and Diastolic Strain Measures in Children: A Systematic Review and Meta-Analysis

PubMed Central

Levy, Philip T.; Sanchez, Aura; Machefsky, Aliza; Fowler, Susan; Holland, Mark R.; Singh, Gautam K.

2014-01-01

Background Establishment of the range of normal values and associated variations of two-dimensional speckle-tracking echocardiography (2DSTE) derived right ventricular (RV) strain is a prerequisite for its routine clinical application in children. The objectives of this study were to perform a meta-analysis of normal ranges of RV longitudinal strain measurements derived by 2DSTE in children and identify confounders that may contribute to differences in reported measures. Methods A systematic review was launched in PubMed, Embase, Scopus, Cochrane, and ClinicTrials.gov. Search hedges were created to cover the concepts of pediatrics, speckle-tracking echocardiography, and right heart ventricle. Two investigators independently identified and included studies if they reported the 2DSTE derived RV strain measures: RV peak global longitudinal strain (pGLS), systolic strain rate (pGLSRs), early diastolic strain rate (pGLSRe), late diastolic strain rate (pGLSRa), or segmental longitudinal strain at the apical, mid, and basal ventricular levels in healthy children. Quality and reporting of the studies were assessed. The weighted mean was estimated by using random-effects with 95% confidence intervals (CI), heterogeneity was assessed by the Cochran's Q statistic and the inconsistency index (I2), and publication bias was evaluated using funnel plots and the Egger test. Effects of demographic, clinical, equipment, and software variables were assessed in a meta-regression. Results The search identified 226 children from 10 studies. The reported normal mean values of pGLS among the studies varied from −20.80% to −34.10% (mean, −29.03%, 95%CI, −31.52% to −26.54%), pGLSRs varied from −1.30 to −2.40 1/sec (mean, −1.88, 95%CI, −2.10 to −1.59), pGLSRe ranged from 1.7 to 2.69 1/sec (mean, 2.34, 95%CI, 2.00 to 2.67) and pGLSRa ranged from 1.00 to 1.30 1/sec (mean, 1.18, 95% CI, 1.04 to 1.33). A significant base-to-apex segmental strain gradient (p <0.05) was observed in the right ventricular free wall. There was significant between-study heterogeneity and inconsistency (I2>88% and p<0.01 for each strain measure), which was not explained by age, gender, body surface area, heart rate, frame rate, tissue tracking methodology, equipment, or software. The meta-regression showed that these effects were not significant determinants of variations among normal ranges of strain values. There was no evidence of publication bias (Egger test, p=0.59). Conclusions This study is the first to define normal values of two-dimensional speckle tracking echocardiographic (2DSTE) derived right ventricle strain in children on the basis of a meta-analysis. The normal mean value in children for RV global strain is −29.03% (95% CI, −31.52% to −26.54%). The normal mean value for RV global systolic strain rate is −1.88 1/sec (95% CI, −2.10 to −1.59). RV segmental strain has a stable base-to-apex gradient that highlights the dominance of deep longitudinal layers of the RV that are aligned base to apex. Variations among different normal ranges do not appear to be dependent on differences in demographic, clinical, or equipment parameters in this meta-analysis. All of the eligible studies used equipment and software from one manufacturer, General Electric (GE). PMID:24582163

Electromechanical models of the ventricles

PubMed Central

Constantino, Jason; Gurev, Viatcheslav

2011-01-01

Computational modeling has traditionally played an important role in dissecting the mechanisms for cardiac dysfunction. Ventricular electromechanical models, likely the most sophisticated virtual organs to date, integrate detailed information across the spatial scales of cardiac electrophysiology and mechanics and are capable of capturing the emergent behavior and the interaction between electrical activation and mechanical contraction of the heart. The goal of this review is to provide an overview of the latest advancements in multiscale electromechanical modeling of the ventricles. We first detail the general framework of multiscale ventricular electromechanical modeling and describe the state of the art in computational techniques and experimental validation approaches. The powerful utility of ventricular electromechanical models in providing a better understanding of cardiac function is then demonstrated by reviewing the latest insights obtained by these models, focusing primarily on the mechanisms by which mechanoelectric coupling contributes to ventricular arrythmogenesis, the relationship between electrical activation and mechanical contraction in the normal heart, and the mechanisms of mechanical dyssynchrony and resynchronization in the failing heart. Computational modeling of cardiac electromechanics will continue to complement basic science research and clinical cardiology and holds promise to become an important clinical tool aiding the diagnosis and treatment of cardiac disease. PMID:21572017

Accuracy criteria voltage electrocardiography left ventricular hypertrophy to distinguish types of left ventricular hypertrophy geometry

NASA Astrophysics Data System (ADS)

Tumbur, O.; Safri, Z.; Hassan, R.

2018-03-01

Different types of left ventricular hypertrophy geometry are associated with different risk of cardiovascular disease. The purpose of this study was to determine the role of various ECG voltages of LVH to distinguish the type of LVH geometry. A cross-sectional study from June to November 2015, 100 patients in Adam Malik Hospital Medan. The result of LVH ECG criteria of Sokolow-Lyon was not met then obtained normal left ventricular geometry with 60% sensitivity, 72.22% specificity, and 71% accuracy. The eccentric type of LVH is obtained when the Cornel Voltage is not met; the sensitivity is 25%, specificity 71.88%, and 55% accuracy. Concentric geometric hypertrophy when the RV6/V5> 1 ratio is satisfied, the sensitivity is 55.56%, specificity 56.36%, and 56% accuracy. The RV6/V5>1 ratio was not met, the concentric geometry type of hypertrophy remodeling was determined with a sensitivity of 55.56%, specificity 49.45%, and 50% accuracy. Conclusions, various LVHECG criteria distinguish the type of LVH geometry. Sokolow-Lyon and Cornel Voltage sensitivity and specificity are better than the RV6/V5 ratio.

'Caterpillar right ventricle': unusual manifestation of a rare disease.

PubMed

Kalliath, Suneesh; Rajesh, Gopalan Nair

2017-01-01

A 66-year-old man presented with abdominal distension and pedal oedema for the past 10 years. He had history of right heart failure on several occasions in the past, and one of these admissions prompted referral to a cardiac specialist. On examination, he had markedly elevated jugular venous pressure with prominent 'y-descent', a tricuspid regurgitation murmur, gross ascites and pedal oedema. A full blood count, routine biochemical screen and serum bicarbonate levels were normal. Right ventricular angiogram revealed a 'caterpillar'-like aneurysm of the right ventricle (RV) apex (figure 1 arrow) with a dilated right ventricular outflow tract and significant tricuspid regurgitation with a dilated right atrium (see online supplementary video 1). Figure 1 A cine angiographic frame of the right ventricle in posteroanterior view, showing a 'caterpillar'-like right ventricle aneurysm (arrow). 10.1136/heartasia-2017-010957.supp3Supplementary file 3. On the basis of the clinical and right ventriculography features, what is the most likely diagnosis for this patient?Arrhythmogenic right ventricular cardiomyopathy (ARVC)Right ventricular endomyocardial fibrosis (RV-EMF) with an RV aneurysmCardiac sarcoidosisCongenital diverticulum of the right ventricle.

Effect of the mitral valve on diastolic flow patterns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seo, Jung Hee; Vedula, Vijay; Mittal, Rajat, E-mail: mittal@jhu.edu

2014-12-15

The leaflets of the mitral valve interact with the mitral jet and significantly impact diastolic flow patterns, but the effect of mitral valve morphology and kinematics on diastolic flow and its implications for left ventricular function have not been clearly delineated. In the present study, we employ computational hemodynamic simulations to understand the effect of mitral valve leaflets on diastolic flow. A computational model of the left ventricle is constructed based on a high-resolution contrast computed-tomography scan, and a physiological inspired model of the mitral valve leaflets is synthesized from morphological and echocardiographic data. Simulations are performed with a diodemore » type valve model as well as the physiological mitral valve model in order to delineate the effect of mitral-valve leaflets on the intraventricular flow. The study suggests that a normal physiological mitral valve promotes the formation of a circulatory (or “looped”) flow pattern in the ventricle. The mitral valve leaflets also increase the strength of the apical flow, thereby enhancing apical washout and mixing of ventricular blood. The implications of these findings on ventricular function as well as ventricular flow models are discussed.« less

Numerical analysis of the effect of T-tubule location on calcium transient in ventricular myocytes.

PubMed

George, Uduak Z; Wang, Jun; Yu, Zeyun

2014-01-01

Intracellular calcium (Ca2+) signaling in cardiac myocytes is vital for proper functioning of the heart. Understanding the intracellular Ca2+ dynamics would give an insight into the functions of normal and diseased hearts. In the current study, spatiotemporal Ca2+ dynamics is investigated in ventricular myocytes by considering Ca2+ release and re-uptake via sarcolemma and transverse tubules (T-tubules), Ca2+ diffusion and buffering in the cytosol, and the blockade of Ca2+ activities associated with the sarcoplasmic reticulum. This study is carried out using a three dimensional (3D) geometric model of a branch of T-tubule extracted from the electron microscopy (EM) images of a partial ventricular myocyte. Mathematical modeling is done by using a system of partial differential equations involving Ca2+, buffers, and membrane channels. Numerical simulation results suggest that a lack of T-tubule structure at the vicinity of the cell surface could increase the peak time of Ca2+ concentration in myocytes. The results also show that T-tubules and mobile buffers play an important role in the regulation of Ca2+ transient in ventricular myocytes.

Comparison of frequencies of left ventricular systolic and diastolic heart failure in Chinese living in Hong Kong.

PubMed

Yip, G W; Ho, P P; Woo, K S; Sanderson, J E

1999-09-01

There is a wide variation (13% to 74%) in the reported prevalence of heart failure associated with normal left ventricular (LV) systolic function (diastolic heart failure). There is no published information on this condition in China. To ascertain the prevalence of diastolic heart failure in this community, 200 consecutive patients with the typical features of congestive heart failure were studied with standard 2-dimensional Doppler echocardiography. A LV ejection fraction (LVEF) >45% was considered normal. The results showed that 12.5% had significant valvular heart disease. Of the remaining 175 patients, 132 had a LVEF >45% (75%). Therefore, 66% of patients with a clinical diagnosis of heart failure had a normal LVEF. Heart failure with normal LV systolic function was more common than systolic heart failure in those >70 years old (65% vs 47%; p = 0.015). Most (57%) had an abnormal relaxation pattern in diastole and 14% had a restrictive filling pattern. In the systolic heart failure group, a restrictive filling pattern was more common (46%). There were no significant differences in the sex distribution, etiology, or prevalence of LV hypertrophy between these 2 heart failure groups. In conclusion, heart failure with a normal LVEF or diastolic heart failure is more common than systolic heart failure in Chinese patients with the symptoms of heart failure. This may be related to older age at presentation and the high prevalence of hypertension in this community.

Derivation of Human Induced Pluripotent Stem (iPS) Cells to Heritable Cardiac Arrhythmias

ClinicalTrials.gov

2017-08-10

Inherited Cardiac Arrythmias; Long QT Syndrome (LQTS); Brugada Syndrome (BrS); Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT); Early Repolarization Syndrome (ERS); Arrhythmogenic Cardiomyopathy (AC, ARVD/C); Hypertrophic Cardiomyopathy (HCM); Dilated Cardiomyopathy (DCM); Muscular Dystrophies (Duchenne, Becker, Myotonic Dystrophy); Normal Control Subjects

Choroidal fissure acts as an overflow device in cerebrospinal fluid drainage: morphological comparison between idiopathic and secondary normal-pressure hydrocephalus

PubMed Central

Yamada, Shigeki; Ishikawa, Masatsune; Iwamuro, Yasushi; Yamamoto, Kazuo

2016-01-01

To clarify the pathogenesis of two different types of adult-onset normal-pressure hydrocephalus (NPH), we investigated cerebrospinal fluid distribution on the high-field three-dimensional MRI. The subarachnoid spaces in secondary NPH were smaller than those in the controls, whereas those in idiopathic NPH were of similar size to the controls. In idiopathic NPH, however, the basal cistern and Sylvian fissure were enlarged in concurrence with ventricular enlargement towards the z-direction, but the convexity subarachnoid space was severely diminished. In this article, we provide evidence that the key cause of the disproportionate cerebrospinal fluid distribution in idiopathic NPH is the compensatory direct CSF communication between the inferior horn of the lateral ventricles and the ambient cistern at the choroidal fissure. In contrast, all parts of the subarachnoid spaces were equally and severely decreased in secondary NPH. Blockage of CSF drainage from the subarachnoid spaces could cause the omnidirectional ventricular enlargement in secondary NPH. PMID:27941913

Automated calculation of the Tei index from signal averaged left ventricular acoustic quantification wave forms.

PubMed

Spencer, Kirk T; Weinert, Lynn; Avi, Victor Mor; Decara, Jeanne; Lang, Roberto M

2002-12-01

The Tei index is a combined measurement of systolic and diastolic left ventricular (LV) performance and may be more useful for the diagnosis of global cardiac dysfunction than either systolic or diastolic measures alone. We sought to determine whether the Tei index could be accurately calculated from LV area waveforms generated with automated border detection. Twenty-four patients were studied in 3 groups: systolic dysfunction, diastolic dysfunction, and normal. The Tei index was calculated both from Doppler tracings and from analysis of LV area waveforms. Excellent agreement was found between Doppler-derived timing intervals and the Tei index with those obtained from averaged LV area waveforms. A significant difference was seen in the Tei index, computed with both Doppler and automated border detection techniques, between the normal group and those with LV systolic dysfunction and subjects with isolated diastolic dysfunction. This study validates the use of LV area waveforms for the automated calculation of the Tei index.

Fulminant antenatal pulmonary oedema in a woman with hypertension and superimposed preeclampsia

PubMed Central

Kubota-Sjogren, Yukiko; Nelson-Piercy, Catherine

2015-01-01

An asymptomatic 40-year-old para 1 black African woman with pre-existing hypertension and a booking blood pressure of 120/80 mm Hg, was admitted with superimposed preeclampsia diagnosed because of worsening hypertension and significant proteinuria at 27+5 weeks gestation. Antenatally, her blood pressure was controlled with labetalol, and blood tests including serum creatinine were within normal limits for pregnancy. Three days later, the patient developed severe hypertension despite treatment, and reported sudden onset severe shortness of breath; oxygen saturations on air dropped to 93%. Auscultation revealed widespread crepitations leading to a working diagnosis of pulmonary oedema. Despite appropriate management, respiratory function continued to deteriorate and she required intubation, ventilation and emergency caesarean section under general anaesthesia. A live male infant was delivered floppy and was intubated and resuscitated. He awaits discharge home on oxygen. The mother's pulmonary oedema resolved postpartum. Echocardiogram showed left ventricular hypertrophy but normal left ventricular function and the patient's hypertension is being controlled on medication. PMID:26607194

Discontinuation of antithrombotic therapy for a year or more in patients with continuous-flow left ventricular assist devices.

PubMed

Pereira, Naveen L; Chen, Dong; Kushwaha, Sudhir S; Park, Soon J

2010-10-01

The recommended anticoagulation regimen during continuous-flow axial left ventricular assist device (LVAD) support is aspirin and warfarin with a targeted international normalized ratio of 2.0-3.0. We report two patients in whom recurrent gastrointestinal bleeding during LVAD support necessitated discontinuation of this anti-thrombotic regimen for a year or more. Despite this, neither patients developed thrombotic complications during 29 patient-months of follow-up. An acquired von Willebrand factor (VWF) abnormality reflected by the absence or decreased abundance of the highest molecular weight multimers was demonstrated in both patients. The gold standard test for platelet function, light transmission platelet aggregometry was measured in one patient and was normal, indicative that the predominant abnormality in the coagulation profile of these patients is an acquired VWF syndrome. Clinical trials are required to address the question whether it is safe to discontinue anticoagulation in LVAD patients with acquired VWF abnormalities.

Evaluation of segmental left ventricular wall motion by equilibrium gated radionuclide ventriculography.

PubMed

Van Nostrand, D; Janowitz, W R; Holmes, D R; Cohen, H A

1979-01-01

The ability of equilibrium gated radionuclide ventriculography to detect segmental left ventricular (LV) wall motion abnormalities was determined in 26 patients undergoing cardiac catheterization. Multiple gated studies obtained in 30 degrees right anterior oblique and 45 degrees left anterior oblique projections, played back in a movie format, were compared to the corresponding LV ventriculograms. The LV wall in the two projections was divided into eight segments. Each segment was graded as normal, hypokinetic, akinetic, dyskinetic, or indeterminate. Thirteen percent of the segments in the gated images were indeterminate; 24 out of 27 of these were proximal or distal inferior wall segments. There was exact agreement in 86% of the remaining segments. The sensitivity of the radionuclide technique for detecting normal versus any abnormal wall motion was 71%, with a specificity of 99%. Equilibrium gated ventriculography is an excellent noninvasive technique for evaluating segmental LV wall motion. It is least reliable in assessing the proximal inferior wall and interventricular septum.

Estimation of left ventricular blood flow parameters: clinical application of patient-specific CFD simulations from 4D echocardiography

NASA Astrophysics Data System (ADS)

Larsson, David; Spühler, Jeannette H.; Günyeli, Elif; Weinkauf, Tino; Hoffman, Johan; Colarieti-Tosti, Massimiliano; Winter, Reidar; Larsson, Matilda

2017-03-01

Echocardiography is the most commonly used image modality in cardiology, assessing several aspects of cardiac viability. The importance of cardiac hemodynamics and 4D blood flow motion has recently been highlighted, however such assessment is still difficult using routine echo-imaging. Instead, combining imaging with computational fluid dynamics (CFD)-simulations has proven valuable, but only a few models have been applied clinically. In the following, patient-specific CFD-simulations from transthoracic dobutamin stress echocardiography have been used to analyze the left ventricular 4D blood flow in three subjects: two with normal and one with reduced left ventricular function. At each stress level, 4D-images were acquired using a GE Vivid E9 (4VD, 1.7MHz/3.3MHz) and velocity fields simulated using a presented pathway involving endocardial segmentation, valve position identification, and solution of the incompressible Navier-Stokes equation. Flow components defined as direct flow, delayed ejection flow, retained inflow, and residual volume were calculated by particle tracing using 4th-order Runge-Kutta integration. Additionally, systolic and diastolic average velocity fields were generated. Results indicated no major changes in average velocity fields for any of the subjects. For the two subjects with normal left ventricular function, increased direct flow, decreased delayed ejection flow, constant retained inflow, and a considerable drop in residual volume was seen at increasing stress. Contrary, for the subject with reduced left ventricular function, the delayed ejection flow increased whilst the retained inflow decreased at increasing stress levels. This feasibility study represents one of the first clinical applications of an echo-based patient-specific CFD-model at elevated stress levels, and highlights the potential of using echo-based models to capture highly transient flow events, as well as the ability of using simulation tools to study clinically complex phenomena. With larger patient studies planned for the future, and with the possibility of adding more anatomical features into the model framework, the current work demonstrates the potential of patient-specific CFD-models as a tool for quantifying 4D blood flow in the heart.

Influence of left ventricular hypertrophy and geometry on diagnostic accuracy of wall motion and perfusion magnetic resonance during dobutamine stress.

PubMed

Gebker, Rolf; Mirelis, Jesus G; Jahnke, Cosima; Hucko, Thomas; Manka, Robert; Hamdan, Ashraf; Schnackenburg, Bernhard; Fleck, Eckart; Paetsch, Ingo

2010-09-01

The purpose of this study was to determine the influence of left ventricular (LV) hypertrophy and geometry on the diagnostic accuracy of wall motion and additional perfusion imaging during high-dose dobutamine/atropine stress magnetic resonance for the detection of coronary artery disease. Combined dobutamine stress magnetic resonance (DSMR)-wall motion and DSMR-perfusion imaging was performed in a single session in 187 patients scheduled for invasive coronary angiography. Patients were classified into 4 categories on the basis of LV mass (normal, ≤ 81 g/m(2) in men and ≤ 62 g/m(2) in women) and relative wall thickness (RWT) (normal, <0.45) as follows: normal geometry (normal mass, normal RWT), concentric remodeling (normal mass, increased RWT), concentric hypertrophy (increased mass, increased RWT), and eccentric hypertrophy (increased mass, normal RWT). Wall motion and perfusion images were interpreted sequentially, with observers blinded to other data. Significant coronary artery disease was defined as ≥ 70% stenosis. In patients with increased LV concentricity (defined by an RWT ≥ 0.45), sensitivity and accuracy of DSMR-wall motion were significantly reduced (63% and 73%, respectively; P<0.05) compared with patients without increased LV concentricity (90% and 88%, respectively; P<0.05). Although accuracy of DSMR-perfusion was higher than that of DSMR-wall motion in patients with concentric hypertrophy (82% versus 71%; P < 0.05), accuracy of DSMR-wall motion was superior to DSMR-perfusion (90% versus 85%; P < 0.05) in patients with eccentric hypertrophy. The accuracy of DSMR-wall motion is influenced by LV geometry. In patients with concentric remodeling and concentric hypertrophy, additional first-pass perfusion imaging during high-dose dobutamine stress improves the diagnostic accuracy for the detection of coronary artery disease.

Angina pectoris in a child with sickle cell anemia.

PubMed

Hamilton, W; Rosenthal, A; Berwick, D; Nadas, A S

1978-06-01

A 7-year-old black boy with sickle cell disease, Wolff-Parkinson-White syndrome, mild left ventricular dysfunction, and normal coronary arteries developed angina pectoris five months after cessation of hypertransfusion therapy. Exercise-induced ECG ST segment depression associated with angina disappeared following transfusion therapy.

A novel hydrodynamic approach of drag-reducing polymers to improve left ventricular hypertrophy and aortic remodeling in spontaneously hypertensive rats.

PubMed

Zhang, Xinlu; Wang, Xu; Hu, Feng; Zhou, Boda; Chen, Hai-Bin; Zha, Daogang; Liu, Yili; Guo, Yansong; Zheng, Lemin; Xiu, Jiancheng

Drag-reducing polymers (DRPs), when added in minute concentrations, have been shown to decrease peripheral vascular resistance. In this study, the effect of DRPs on the hypertension-induced left ventricular hypertrophy and aortic remodeling was evaluated in spontaneously hypertensive rats (SHR). Male SHR and age-matched Wistar rats were divided into four groups and received intravenous injection of normal saline (NS) or DRPs. Body weight (BW), heart rate (HR) and systolic blood pressure (SBP) were measured. Echocardiography was used to evaluate the changes in left ventricle (LV) function and global wall motion. The LV and aorta were stained by hematoxylin and eosin. Cell size of cardiomyocytes and aortic medial thickness were evaluated for each section. The expression of endothelin-1 (ET-1) of LV and aorta was examined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry. There was no significant difference in the increase of SBP among SHR + NS, SHR + 10DRP and SHR + 20DRP groups. SHR + NS group had markedly smaller left ventricular end-systolic diameter and left ventricular end-diastolic diameter but bigger anterior and posterior systolic wall thicknesses, while there was no significant difference in fractional shortening and ejection fraction. The cross-sectional areas (CSAs) of cardiomyocytes and the medial thickness of the aorta in SHR + 10 (ppm) DRP and SHR + 20 (ppm) DRP groups were significantly reduced compared with SHR + NS group. The expression of ET-1 in SHR + 10DRP and SHR + 20DRP groups was significantly attenuated. These results suggest that chronic treatment with DRPs can protect against left ventricular hypertrophy and aortic remodeling. DRPs may offer a new approach to the treatment of left ventricular hypertrophy and aortic remodeling caused by hypertension.

A novel hydrodynamic approach of drag-reducing polymers to improve left ventricular hypertrophy and aortic remodeling in spontaneously hypertensive rats

PubMed Central

Zhang, Xinlu; Wang, Xu; Hu, Feng; Zhou, Boda; Chen, Hai-Bin; Zha, Daogang; Liu, Yili; Guo, Yansong; Zheng, Lemin; Xiu, Jiancheng

2016-01-01

Drag-reducing polymers (DRPs), when added in minute concentrations, have been shown to decrease peripheral vascular resistance. In this study, the effect of DRPs on the hypertension-induced left ventricular hypertrophy and aortic remodeling was evaluated in spontaneously hypertensive rats (SHR). Male SHR and age-matched Wistar rats were divided into four groups and received intravenous injection of normal saline (NS) or DRPs. Body weight (BW), heart rate (HR) and systolic blood pressure (SBP) were measured. Echocardiography was used to evaluate the changes in left ventricle (LV) function and global wall motion. The LV and aorta were stained by hematoxylin and eosin. Cell size of cardiomyocytes and aortic medial thickness were evaluated for each section. The expression of endothelin-1 (ET-1) of LV and aorta was examined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry. There was no significant difference in the increase of SBP among SHR + NS, SHR + 10DRP and SHR + 20DRP groups. SHR + NS group had markedly smaller left ventricular end-systolic diameter and left ventricular end-diastolic diameter but bigger anterior and posterior systolic wall thicknesses, while there was no significant difference in fractional shortening and ejection fraction. The cross-sectional areas (CSAs) of cardiomyocytes and the medial thickness of the aorta in SHR + 10 (ppm) DRP and SHR + 20 (ppm) DRP groups were significantly reduced compared with SHR + NS group. The expression of ET-1 in SHR + 10DRP and SHR + 20DRP groups was significantly attenuated. These results suggest that chronic treatment with DRPs can protect against left ventricular hypertrophy and aortic remodeling. DRPs may offer a new approach to the treatment of left ventricular hypertrophy and aortic remodeling caused by hypertension. PMID:28008249

Mapping correlations between ventricular expansion and CSF amyloid and tau biomarkers in 240 subjects with Alzheimer’s disease, mild cognitive impairment and elderly controls

PubMed Central

Chou, Yi-Yu; Leporé, Natasha; Avedissian, Christina; Madsen, Sarah K.; Parikshak, Neelroop; Hua, Xue; Shaw, Leslie M.; Trojanowski, John Q.; Weiner, Michael W.; Toga, Arthur W.; Thompson, Paul M.

2009-01-01

Automated ventricular mapping with multi-atlas fluid image alignment reveals genetic effects in Alzheimer’s disease, NeuroImage 40(2): 615–630); with this method, we calculated minimal numbers of subjects needed to detect correlations between clinical scores and ventricular maps. We also assessed correlations between emerging CSF biomarkers of Alzheimer’s disease pathology and localizable deficits in the brain, in 80 AD, 80 mild cognitive impairment (MCI), and 80 healthy controls from the Alzheimer’s Disease Neuroimaging Initiative. Six expertly segmented images and their embedded parametric mesh surfaces were fluidly registered to each brain; segmentations were averaged within subjects to reduce errors. Surface-based statistical maps revealed powerful correlations between surface morphology and 4 variables: (1) diagnosis, (2) depression severity, (3) cognitive function at baseline, and (4) future cognitive decline over the following year. Cognitive function was assessed using the mini-mental state exam (MMSE), global and sum-of-boxes clinical dementia rating (CDR) scores, at baseline and 1-year follow-up. Lower CSF Aβ1–42 protein levels, a biomarker of AD pathology assessed in 138 of the 240 subjects, were correlated with lateral ventricular expansion. Using false discovery rate (FDR) methods, 40 and 120 subjects, respectively, were needed to discriminate AD and MCI from normal groups. 120 subjects were required to detect correlations between ventricular enlargement and MMSE, global CDR, sum-of-boxes CDR and clinical depression scores. Ventricular expansion maps correlate with pathological and cognitive measures in AD, and may be useful in future imaging-based clinical trials. PMID:19236926

Dissociation of hemodynamic and electrocardiographic indexes of myocardial ischemia in pigs with hibernating myocardium and sudden cardiac death.

PubMed

Pizzuto, Matthew F; Suzuki, Gen; Banas, Michael D; Heavey, Brendan; Fallavollita, James A; Canty, John M

2013-06-15

Many survivors of sudden cardiac death (SCD) have normal global ventricular function and severe coronary artery disease but no evidence of symptomatic ischemia or infarction before the development of lethal ventricular arrhythmias, and the trigger for ventricular tachycardia (VT)/ventricular fibrillation (VF) remains unclear. We sought to identify the role of spontaneous ischemia and temporal hemodynamic factors preceding SCD using continuous telemetry of left ventricular (LV) pressure and the ECG for periods up to 5 mo in swine (n = 37) with hibernating myocardium who experience spontaneous VT/VF in the absence of heart failure or infarction. Hemodynamics and ST deviation at the time of VT/VF were compared with survivors with hibernating myocardium as well as sham controls. All episodes of VT/VF occurred during sympathetic activation and were initiated by single premature ventricular contractions, and the VT degenerated into VF in ∼ 30 s. ECG evidence of ischemia was infrequent and no different from those that survived. Baseline hemodynamics were no different among groups, but LV end-diastolic pressure during sympathetic activation was higher at the time of SCD (37 ± 4 vs. 26 ± 4 mmHg, P < 0.05) and the ECG demonstrated QT shortening (155 ± 4 vs. 173 ± 5 ms, P < 0.05). The week before SCD, both parameters were no different from survivors. These data indicate that there are no differences in the degree of sympathetic activation or hemodynamic stress when VT/VF develops in swine with hibernating myocardium. The transiently elevated LV end-diastolic pressure and QT shortening preceding VT/VF raises the possibility that electrocardiographically silent subendocardial ischemia and/or mechanoelectrical feedback serve as a trigger for the development of SCD in chronic ischemic heart disease.

The impact of the metabolic syndrome on the outcome after aortic valve replacement.

PubMed

Tadic, Marijana; Vukadinovic, Davor; Cvijanovic, Dane; Celic, Vera; Kocica, Mladen; Putnik, Svetozar; Ivanovic, Branislava

2014-10-01

The aim of this study was to examine the influence of the metabolic syndrome on the left ventricular geometry as well as on the early and mid-time outcome in patients with aortic stenosis who underwent aortic valve replacement. The study included 182 patients who underwent aortic valve replacement due to aortic stenosis. The metabolic syndrome was defined by the presence of at least three AHA-NHLB (American Heart Association/National Heart, Lung and Blood Institute) criteria. All the patients were followed for at least 2 years after the surgery. The metabolic syndrome did not influence the severity of aortic stenosis (mean gradient and aortic valve area). However, the metabolic syndrome was associated with the reduced prevalence of the normal left ventricular geometry and the increased risk of concentric left ventricular hypertrophy in patients with aortic stenosis. Among the metabolic syndrome criteria, only increased blood pressure was simultaneously associated with the short-term and mid-term outcome, independently of other risk factors. Increased fasting glucose level was an independent predictor of the only 30-day outcome after the valve replacement. The metabolic syndrome and left ventricular hypertrophy were, independently of hypertension and diabetes, associated with the 30-day outcome, as well as incidence of major cerebrovascular and cardiovascular events in the 2-year postoperative period. The metabolic syndrome does not change severity of the aortic stenosis, but significantly impacts the left ventricular remodeling in these patients. The metabolic syndrome and left ventricular hypertrophy, irrespective of hypertension and diabetes, are predictors of the short-term and mid-term outcome of patients with aortic stenosis who underwent aortic valve replacement.

Quantitative Evaluation of the Fetal Right and Left Ventricular Fractional Area Change Using Speckle Tracking Technology.

PubMed

DeVore, Greggory R; Klas, Berthold; Satou, Gary; Sklansky, Mark

2018-03-14

The purpose of this study was to measure the fractional area change (FAC) of the right and left ventricles in normal fetal hearts between 20 and 40 weeks of gestation using speckle-tracking software. The 4-chamber view of the fetal heart was obtained in 200 control fetuses between 20 and 40 weeks of gestation. The FAC was computed from the ventricular areas [((end-diastolic area) - (end-systolic area)/(end-diastolic area)) x 100] for the right and left ventricles and regressed against 7 independent biometric and age variables. The FAC was correlated with longitudinal fractional shortening (LFS) [((end-diastolic longitudinal length) - (end-systolic longitudinal length) /(end-diastolic longitudinal length)) x 100] obtained from the mid ventricular basal-apical lengths of the right and left ventricular chambers and the transverse fractional shortening (TFS) [((end-diastolic transverse length) - (end-systolic transverse length)/(end-diastolic transverse length)) x 100] from three transverse positions (base, mid, apical) located within each ventricular chamber. To evaluate potential clinical utility, the FAC, LFS, and TFS results were examined in 9 fetuses with congenital heart defects (CHD). Regression analysis demonstrated significant associations between the FAC and the biometric and age independent variables (R 2 = 0.13 - 0.15). The FAC was significantly correlated with the LFS (R 2 =0.18 to 0.28) and TFS (R 2 = 0.13 to 0.33). The 9 fetuses with CHD illustrated the interrelationship between the FAC, LFS, and TFS when identifying abnormal ventricular function. This study reports results from measuring the FAC of the right and left ventricles, and demonstrates a correlation with longitudinal fractional shortening (LFS) and transverse fractional shortening (TFS). This article is protected by copyright. All rights reserved.

Modification of a Volume-Overload Heart Failure Model to Track Myocardial Remodeling and Device-Related Reverse Remodeling

PubMed Central

Tuzun, Egemen; Bick, Roger; Kadipasaoglu, Cihan; Conger, Jeffrey L.; Poindexter, Brian J.; Gregoric, Igor D.; Frazier, O. H.; Towbin, Jeffrey A.; Radovancevic, Branislav

2011-01-01

Purpose. To provide an ovine model of ventricular remodeling and reverse remodeling by creating congestive heart failure (CHF) and then treating it by implanting a left ventricular assist device (LVAD). Methods. We induced volume-overload heart failure in 2 sheep; 20 weeks later, we implanted an LVAD and assessed recovery 11 weeks thereafter. We examined changes in histologic and hemodynamic data and levels of cellular markers of CHF. Results. After CHF induction, we found increases in LV end-diastolic pressure, LV systolic and diastolic dimensions, wall thickness, left atrial diameter, and atrial natriuretic protein (ANP) and endothelin-1 (ET-1) levels; β-adrenergic receptor (BAR) and dystrophin expression decreased markedly. Biopsies confirmed LV remodeling. After LVAD support, LV systolic and diastolic dimensions, wall thickness, and mass, and ANP and ET-1 levels decreased. Histopathologic and hemodynamic markers improved, and BAR and dystrophin expression normalized. Conclusions. We describe a successful sheep model for ventricular and reverse remodeling. PMID:22347659

Vortex Formation Time is Not an Index of Ventricular Function

PubMed Central

Vlachos, Pavlos P.; Little, William C.

2015-01-01

The diastolic intraventricular ring vortex formation and pinch-off process may provide clinically useful insights into diastolic function in health and disease. The vortex ring formation time (FT) concept, based on hydrodynamic experiments dealing with unconfined (large tank) flow, has attracted considerable attention and popularity. Dynamic conditions evolving within the very confined space of a filling, expansible ventricular chamber with relaxing and rebounding viscoelastic muscular boundaries, diverge from unconfined (large tank) flow and encompass rebounding walls’ suction and myocardial relaxation. Indeed, clinical/physiological findings seeking validation in vivo failed to support the notion that FT is an index of normal/abnormal diastolic ventricular function. Therefore, FT as originally proposed cannot and should not be utilized as such an index. Evidently, physiologically accurate models accounting for coupled hydrodynamic and (patho)physiological myocardial wall interactions with the intraventricular flow are still needed to enhance our understanding and yield diastolic function indices useful and reliable in the clinical setting. PMID:25609509

Aconite poisoning with arrhythmia and shock.

PubMed

Tak, Sandeep; Lakhotia, Manoj; Gupta, Alok; Sagar, Amit; Bohra, Gopal; Bajari, Rajesh

2016-09-01

A 55-year-old male presented with history of nausea, vomiting, palpitation paresthesis and profuse sweating in emergency department 2h after ingestion of "Bachnaag" (Aconite) root. Examination revealed shock with irregular pulses. Initial ECG showed frequent multifocal ventricular ectopics (VE), which later turned to short runs of ventricular tachycardia (VT). Immediate gastric lavage was done and activated charcoal given. Patient was treated with fluid resuscitation without any improvement in blood pressure. Patient was started on nor-adrenaline infusion with gradual recovery from hypotension over a period of 6h, but support was continued for 48h. Amiodarone was started to control ventricular excitability, which persisted over 72h with gradual decrease in frequency of VT and VE. Patient was discharged with normal sinus rhythm on oral amiodarone on 5th day of hospitalization. On follow-up after 2 weeks patient was totally asymptomatic and amiodarone was stopped. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Right Heart Vortex Entrainment Volume and Right Ventricular Diastolic Dysfunction

NASA Astrophysics Data System (ADS)

Browning, James; Hertzberg, Jean; Fenster, Brett; Schroeder, Joyce

2014-11-01

Recent advances in cardiac magnetic resonance imaging (CMR) have allowed for the 3-dimensional characterization of blood flow in the right ventricle (RV) and right atrium (RA). In this study, we investigate and quantify differences in the characteristics of coherent rotating flow structures (vortices) in the RA and RV between subjects with right ventricular diastolic dysfunction (RVDD) and normal controls. Fifteen RVDD subjects and 10 age-matched controls underwent same day 3D time resolved CMR and echocardiography. Echocardiography was used to determine RVDD stage as well as pulmonary artery systolic pressure (PASP). CMR data was used for RA and RV vortex quantification and visualization during early and late ventricular diastole. RA and RV vortex entrainment volume is quantified and visualized using the Lambda-2 criterion, and the results are compared between healthy subjects and those with RVDD. The resulting trends are discussed and hypotheses are presented regarding differences in vortex characteristics between healthy and RVDD subjects cohorts.

77-year-old female with syncope.

PubMed

Abdelsalam, Mahmoud A; Geske, Jeffrey B

2017-02-15

A 77-year-old female was referred for evaluation of an episode of syncope while eating breakfast. There was no history of fall, syncope, prodrome, dyspnoea, chest discomfort or palpitations. Medical history was notable for hyperlipidaemia and treated hypertension. Blood pressure was 140/90 mm Hg, pulse 85  beats per minute (BPM). No murmurs were present on cardiac examination. ECG revealed normal sinus rhythm with left ventricular (LV) hypertrophy (see online supplementary figure S1). Holter monitor demonstrated rare premature ventricular complexes (<1% of beats), without heart block or ventricular tachycardia. Transthoracic echocardiogram is shown in figure 1. Which of the following is the explanation for the flow indicated by the yellow arrow? Aortic stenosisCoronary artery flow, indicative of coronary fistulaHypertrophic cardiomyopathy with apical pouchHypertensive heart diseaseMitral stenosis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Left Ventricular Diastolic and Systolic Material Property Estimation from Image Data

PubMed Central

Krishnamurthy, Adarsh; Villongco, Christopher; Beck, Amanda; Omens, Jeffrey; McCulloch, Andrew

2015-01-01

Cardiovascular simulations using patient-specific geometries can help researchers understand the mechanical behavior of the heart under different loading or disease conditions. However, to replicate the regional mechanics of the heart accurately, both the nonlinear passive and active material properties must be estimated reliably. In this paper, automated methods were used to determine passive material properties while simultaneously computing the unloaded reference geometry of the ventricles for stress analysis. Two different approaches were used to model systole. In the first, a physiologically-based active contraction model [1] coupled to a hemodynamic three-element Windkessel model of the circulation was used to simulate ventricular ejection. In the second, developed active tension was directly adjusted to match ventricular volumes at end-systole while prescribing the known end-systolic pressure. These methods were tested in four normal dogs using the data provided for the LV mechanics challenge [2]. The resulting end-diastolic and end-systolic geometry from the simulation were compared with measured image data. PMID:25729778

Concomitant Wolff-Parkinson-White and Atrioventricular Nodal Reentrant Tachycardia: Which Pathway to Ablate?

PubMed

Sarsam, Sinan; Sidiqi, Ibrahim; Shah, Dipak; Zughaib, Marcel

2015-12-11

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common form of supraventricular tachycardia. In contrast, Wolff-Parkinson-White (WPW) pattern consists of an accessory pathway, which may result in the development of ventricular arrhythmias. Frequent tachycardia caused by AVNRT and accessory pathways may play a role in left ventricular systolic dysfunction. A 54-year-old man presented with palpitations and acute decompensated congestive heart failure. His baseline EKG showed Wolff-Parkinson-White (WPW) pattern. While hospitalized, he had an episode of atrioventricular nodal reentrant tachycardia (AVNRT). He underwent radiofrequency catheter ablation for AVNRT, and his accessory pathway was also ablated even though its conduction was found to be weak. He was clinically doing well on follow-up visit, with resolution of his heart failure symptoms and normalization of left ventricular function on echocardiography. This case raises the question whether the accessory pathway plays a role in the development of systolic dysfunction, and if there is any role for ablation in patients with asymptomatic WPW pattern.

Prediction of Left Ventricular Filling Pressure by 3-Dimensional Speckle-Tracking Echocardiography in Patients With Coronary Artery Disease.

PubMed

Ma, Hong; Xie, Rong-Ai; Gao, Li-Jian; Zhang, Jin-Ping; Wu, Wei-Chun; Wang, Hao

2015-10-01

The purpose of this study was to investigate the diagnostic value of 3-dimensional (3D) speckle-tracking echocardiography for estimating left ventricular filling pressure in patients with coronary artery disease (CAD) and a preserved left ventricular ejection fraction. Altogether, 84 patients with CAD and 30 age- and sex-matched healthy control participants in sinus rhythm were recruited prospectively. All participants underwent conventional and 3D speckle-tracking echocardiography. Global strain values were automatically calculated by 3D speckle-tracking analysis. The left ventricular end-diastolic pressure (LVEDP) was determined invasively by left heart catheterization. Echocardiography and cardiac catheterization were performed within 24 hours. Compared with the controls, patients with CAD showed lower global longitudinal strain, global circumferential strain, global area strain, and global radial strain. Patients with CAD who had an elevated LVEDP had much lower levels of all 4 3D-speckle-tracking echocardiographic variables. Pearson correlation analysis revealed that the LVEDP correlated positively with the early transmitral flow velocity/early diastolic myocardial velocity (E/E') ratio, global longitudinal strain, global circumferential strain, and global area strain. It correlated negatively with global radial strain. Receiver operating characteristic curve analysis revealed that these 3D speckle-tracking echocardiographic indices could effectively predict elevated left ventricular filling pressure (LVEDP >15 mm Hg) in patients with CAD (areas under the curve: global longitudinal strain, 0.78; global radial strain, 0.77; global circumferential strain, 0.75; and global area strain, 0.74). These parameters, however, showed no advantages over the commonly used E/E' ratio (area under the curve, 0.84). Three-dimensional speckle-tracking echocardiography was a practical technique for predicting elevated left ventricular filling pressure, but it might not be superior to the commonly used E/E' ratio in patients with CAD who have a normal left ventricular ejection fraction. © 2015 by the American Institute of Ultrasound in Medicine.

Exaggerated coronary vasoconstriction limits muscle metaboreflex-induced increases in ventricular performance in hypertension

PubMed Central

Spranger, Marty D.; Kaur, Jasdeep; Sala-Mercado, Javier A.; Krishnan, Abhinav C.; Abu-Hamdah, Rania; Alvarez, Alberto; Machado, Tiago M.; Augustyniak, Robert A.

2017-01-01

Increases in myocardial oxygen consumption during exercise mainly occur via increases in coronary blood flow (CBF) as cardiac oxygen extraction is high even at rest. However, sympathetic coronary constrictor tone can limit increases in CBF. Increased sympathetic nerve activity (SNA) during exercise likely occurs via the action of and interaction among activation of skeletal muscle afferents, central command, and resetting of the arterial baroreflex. As SNA is heightened even at rest in subjects with hypertension (HTN), we tested whether HTN causes exaggerated coronary vasoconstriction in canines during mild treadmill exercise with muscle metaboreflex activation (MMA; elicited by reducing hindlimb blood flow by ~60%) thereby limiting increases in CBF and ventricular performance. Experiments were repeated after α1-adrenergic blockade (prazosin; 75 µg/kg) and in the same animals following induction of HTN (modified Goldblatt 2K1C model). HTN increased mean arterial pressure from 97.1 ± 2.6 to 132.1 ± 5.6 mmHg at rest and MMA-induced increases in CBF, left ventricular dP/dtmax, and cardiac output were markedly reduced to only 32 ± 13, 26 ± 11, and 28 ± 12% of the changes observed in control. In HTN, α1-adrenergic blockade restored the coronary vasodilation and increased in ventricular function to the levels observed when normotensive. We conclude that exaggerated MMA-induced increases in SNA functionally vasoconstrict the coronary vasculature impairing increases in CBF, which limits oxygen delivery and ventricular performance in HTN. NEW & NOTEWORTHY We found that metaboreflex-induced increases in coronary blood flow and ventricular contractility are attenuated in hypertension. α1-Adrenergic blockade restored these parameters toward normal levels. These findings indicate that the primary mechanism mediating impaired metaboreflex-induced increases in ventricular function in hypertension is accentuated coronary vasoconstriction. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/metaboreflex-induced-functional-coronary-vasoconstriction/. PMID:27769997

A novel cardiac MR chamber volume model for mechanical dyssynchrony assessment

NASA Astrophysics Data System (ADS)

Song, Ting; Fung, Maggie; Stainsby, Jeffrey A.; Hood, Maureen N.; Ho, Vincent B.

2009-02-01

A novel cardiac chamber volume model is proposed for the assessment of left ventricular mechanical dyssynchrony. The tool is potentially useful for assessment of regional cardiac function and identification of mechanical dyssynchrony on MRI. Dyssynchrony results typically from a contraction delay between one or more individual left ventricular segments, which in turn leads to inefficient ventricular function and ultimately heart failure. Cardiac resynchronization therapy has emerged as an electrical treatment of choice for heart failure patients with dyssynchrony. Prior MRI techniques have relied on assessments of actual cardiac wall changes either using standard cine MR images or specialized pulse sequences. In this abstract, we detail a semi-automated method that evaluates dyssynchrony based on segmental volumetric analysis of the left ventricular (LV) chamber as illustrated on standard cine MR images. Twelve sectors each were chosen for the basal and mid-ventricular slices and 8 sectors were chosen for apical slices for a total of 32 sectors. For each slice (i.e. basal, mid and apical), a systolic dyssynchrony index (SDI) was measured. SDI, a parameter used for 3D echocardiographic analysis of dyssynchrony, was defined as the corrected standard deviation of the time at which minimal volume is reached in each sector. The SDI measurement of a healthy volunteer was 3.54%. In a patient with acute myocardial infarction, the SDI measurements 10.98%, 16.57% and 1.41% for basal, mid-ventricular and apical LV slices, respectively. Based on published 3D echocardiogram reference threshold values, the patient's SDI corresponds to moderate basal dysfunction, severe mid-ventricular dysfunction, and normal apical LV function, which were confirmed on echocardiography. The LV chamber segmental volume analysis model and SDI is feasible using standard cine MR data and may provide more reliable assessment of patients with dyssynchrony especially if the LV myocardium is thin or if the MR images have spatial resolution insufficient for proper resolution of wall thickness-features problematic for dyssynchrony assessment using existing MR techniques.

Left ventricular functions in children with newly diagnosed Graves' disease. A single-center study from Upper Egypt.

PubMed

Metwalley, Kotb Abbass; Farghaly, Hekma Saad; Abdelhamid, Abdelrahman

2018-01-01

This study aimed to evaluate the left ventricular (LV) functions in a cohort of children with Graves' disease (GD). This is a cross-sectional case-control study. It included 36 children with GD and 36 healthy children matched for age and gender. Thyroid hormones (TSH, FT4, and FT3) and anti-thyroid autoantibodies [anti-thyroid peroxidase (anti-TPO), thyrotropin receptor (TRAbs), and thyroglobulin antibodies] were measured. Conventional and tissue Doppler imaging (TDI) echocardiographies were used to assess left ventricular systolic and diastolic functions. LV mass index (LVMI) and myocardial performance index (MPI) were also measured. Compared to healthy children, conventional echocardiography of patients with GD revealed higher LVMI (P = 0.001) indicating LV hypertrophy but normal LV functions while TDI revealed lower Em/Am ratio indicating LV diastolic dysfunction (P = 0.001). Significant correlations were reported between FT4 with LVMI (P = 0.05), Em/Am (P = 0.01), and MPI (P = 0.01). In multivariate analysis, a positive correlation was identified between FT4 with MPI (OR = 1.17; 95% CI = 1.09-1.15; P = 0.001). Children with newly diagnosed GD may have significant subclinical changes in LV structure and function (diastolic and global). TDI is more sensitive than conventional Doppler in detecting LV dysfunction. These findings highlight the importance of early monitoring of children with GD for left ventricular mass index and diastolic function. What is Known: • There is an increased risk for cardiac abnormalities in children with Graves' disease (GD). • Limited studies assessed left ventricular function in patients with GD. What is New: • Children with newly diagnosed GD may have significant subclinical changes in left ventricular structure and functions. • Children with newly diagnosed GD should be monitored for left ventricular mass index and diastolic function.

Quantitative Computed Tomography Ventriculography for Assessment and Monitoring of Hydrocephalus: A Pilot Study and Description of Method in Subarachnoid Hemorrhage.

PubMed

Multani, Jasjit Singh; Oermann, Eric Karl; Titano, Joseph; Mascitelli, Justin; Nicol, Kelly; Feng, Rui; Skovrlj, Branko; Pain, Margaret; Mocco, J D; Bederson, Joshua B; Costa, Anthony; Shrivastava, Raj

2017-08-01

There is no facile quantitative method for monitoring hydrocephalus (HCP). We propose quantitative computed tomography (CT) ventriculography (qCTV) as a novel computer vision tool for empirically assessing HCP in patients with subarachnoid hemorrhage (SAH). Twenty patients with SAH who were evaluated for ventriculoperitoneal shunt (VPS) placement were selected for inclusion. Ten patients with normal head computed tomography (CTH) findings were analyzed as negative controls. CTH scans were segmented both manually and automatically (by qCTV) to generate measures of ventricular volume. The median manually calculated ventricular volume was 36.1 cm 3 (interquartile range [IQR], 30-115 cm 3 ), which was similar to the median qCTV measured volume of 37.5 cm 3 (IQR, 32-118 cm 3 ) (P = 0.796). Patients undergoing VPS placement demonstrated an increase in median ventricular volume on qCTV from 21 cm 3 to 40 cm 3 on day T-2 and to 51 cm 3 by day 0, a change of 144%. This is in contrast to patients who did not require shunting, in whom median ventricular volume decreased from 16 cm 3 to 14 cm 3 on day T-2 and to 13 cm 3 by day 0, with an average overall volume decrease 19% (P = 0.001). The average change in ventricular volume predicted which patients would require VPS placement, successfully identifying 7 of 10 patients (P = 0.004). Using an optimized cutoff of a change in ventricular volume of 2.5 cm 3 identified all patients who went on to require VPS placement (10 of 10; P = 0.011). qCTV is a reliable means of quantifying ventricular volume and hydrocephalus. This technique offers a new tool for monitoring neurosurgical patients for hydrocephalus, and may be beneficial for use in future research studies, as well as in the routine care of patients with hydrocephalus. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of left ventricular function by bedside ultrasound in acute toxic myocarditis.

PubMed

Brown, Cara; Budhram, Gavin

2013-10-01

Myocarditis can be difficult to diagnose in the Emergency Department (ED) due to the lack of classic symptoms and the wide variation in presentations. Poor cardiac contractility is a common finding in myocarditis and can be evaluated by bedside ultrasound. To demonstrate the utility of fractional shortening measurements as an estimation of left ventricular function during bedside cardiac ultrasound evaluation in the ED. A 54-year-old man presented to the ED complaining of 3 days of chest tightness, palpitations, and dyspnea, as well as persistent abdominal pain and vomiting. An electrocardiogram (ECG) showed sinus tachycardia with presumably new ST-segment elevation and signs of an incomplete right bundle branch block. A bedside echocardiogram was performed by the emergency physician that showed poor left ventricular function by endocardial fractional shortening measurements. On further questioning, the patient revealed that for the past 2 weeks he had been regularly huffing a commercially available compressed air duster. Based on these history and examination findings, the patient was given a presumptive diagnosis of toxic myocarditis. A follow-up echocardiogram approximately 7 weeks later demonstrated resolution of the left ventricular systolic dysfunction and his ECG findings normalized. Cardiac ultrasound findings of severely reduced global function measured by endocardial fractional shortening were seen in this patient and supported the diagnosis of myocarditis. Endocardial fractional shortening is a useful means of easily evaluating and documenting left ventricular function and can be performed at the bedside in the ED. Copyright © 2013 Elsevier Inc. All rights reserved.

Echocardiographic assessment of left ventricular diastolic function.

PubMed

Pirat, Bahar; Zoghbi, William A

2007-09-01

Assessment of diastolic function and left ventricular filling pressures in the setting of both normal and reduced systolic function is of major importance particularly in patients with dyspnea. Since multiple echocardiography parameters are used to assess diastolic function each with some limitations, a comprehensive approach should be applied. Transmitral Doppler flow should be evaluated in combination with newer, less load dependent Doppler techniques. Tissue Doppler imaging provides accurate, well validated data regarding diastolic properties and filling pressures of the left ventricle. Tissue Doppler imaging should be the part of a routine echocardiography study due to its ease of use and high reproducibility. Pulmonary vein Doppler and flow propagation velocity should be incorporated into the evaluation when needed.

Bi-ventricular finite element model of right ventricle overload in the healthy rat heart.

PubMed

Masithulela, Fulufhelo

2016-11-25

The recognition of RV overpressure is critical to human life, as this may signify morbidity and mortality. Right ventricle (RV) dysfunction is understood to have an impact on the performance of the left ventricle (LV), but the mechanisms remain poorly understood. It is understood that ventricular compliance has the ability to affect cardiac performance. In this study, a bi-ventricular model of the rat heart was used in preference to other, single-ventricle models. Finite element analysis (FEA) of the bi-ventricular model provides important information on the function of the healthy heart. The passive myocardium was modelled as a nearly incompressible, hyperelastic, transversely isotropic material using finite element (FE) methods. Bi-ventricular geometries of healthy rat hearts reconstructed from magnetic resonance images were imported in Abaqus©. In simulating the normal passive filling of the rat heart, pressures of 4.8 kPa and 0.0098 kPa were applied to the inner walls of the LV and RV respectively. In addition, to simulate the overpressure of the RV, pressures of 2.4 kPa and 4.8 kPa were applied to the endocardial walls of the LV and RV respectively. As boundary conditions, the circumferential and longitudinal displacements at the base were set to zero. The radial displacements at the base were left free. The results show that the average circumferential stress at the mid-wall in the overloaded model increased from 2.8 kPa to 18.2 kPa. The average longitudinal stress increased from 1.5 kPa to 9.7 kPa. Additionally, in the radial direction, the average stress increased from 0.1 kPa to 0.6 kPa in the mid-wall. The average circumferential strain was found to be 0.138 and 0.100 on the endocardium of the over pressured and healthy model respectively. The average circumferential stress at the epicardium, mid-wall and endocardium in the case of a normal heart is 10 times lower than in the overloaded heart model. The finite analysis method is able to provide insights into the behaviour of the over pressured model (myocardium). In the overloaded model the high stresses and strains were observed on the septal wall. The bi-ventricular model was shown to provide useful information relating to the over pressured ventricle. The possible heart dysfunction may be attributable to high stress and strain in the over pressured heart.

Magnesium in cardioplegia: Is it necessary?

PubMed Central

Shakerinia, Tooraj; Ali, Idris M.; Sullivan, John A.P.

1996-01-01

Objective To study the effectiveness of magnesium in cardioplegic solution in preventing postoperative arrhythmias and perioperative ischemia. Design Randomized, control study. Setting The cardiovascular surgery division of a major referral centre for the maritime provinces of Canada. Patients Fifty patients scheduled to undergo coronary artery bypass who had a normal ejection fraction, normal preoperative serum magnesium level and no history of atrial or ventricular arrhythmia were randomized into two groups of 25 patients. One group received magnesium sulfate (15 mmol/L) in the cardioplegic solution (group 1), the other (control) group did not receive magnesium sulfate in the cardioplegic solution (group 2). Intervention Coronary artery bypass grafting during which myocardial protection was provided by intermittent cold blood cardioplegia. Outcome Measures Postoperative serum magnesium levels, cardiac-related death, infarction and arrhythmias. Results All group 2 patients had a lower postoperative serum magnesium level than group 1 patients. There were no cardiac-related deaths in either group. More group 2 patients had ischemic electrocardiographic changes than group 1 patients (p < 0.03). Non-Q-wave myocardial infarction occurred in two patients (one in each group). Eight patients in group 2 had atrial fibrillation compared with five patients in group 1. Ventricular ectopia occurred significantly (p < 0.01) more frequently in group 2 than in group 1. Conclusion The addition of magnesium to the cardioplegic solution is beneficial in reducing the incidence of perioperative ischemia and ventricular arrhythmia in patients who undergo coronary bypass grafting. PMID:8857989

Heart rate variability in idiopathic dilated cardiomyopathy: relation to disease severity and prognosis.

PubMed Central

Yi, G.; Goldman, J. H.; Keeling, P. J.; Reardon, M.; McKenna, W. J.; Malik, M.

1997-01-01

OBJECTIVE: To assess the clinical importance of heart rate variability (HRV) in patients with idiopathic dilated cardiomyopathy (DCM). PATIENTS AND METHODS: Time domain analysis of 24 hour HRV was performed in 64 patients with DCM, 19 of their relatives with left ventricular enlargement (possible early DCM), and 33 healthy control subjects. RESULTS: Measures of HRV were reduced in patients with DCM compared with controls (P < 0.05). HRV parameters were similar in relatives and controls. Measures of HRV were lower in DCM patients in whom progressive heart failure developed (n = 28) than in those who remained clinically stable (n = 36) during a follow up of 24 (20) months (P = 0.0001). Reduced HRV was associated with NYHA functional class, left ventricular end diastolic dimension, reduced left ventricular ejection fraction, and peak exercise oxygen consumption (P < 0.05) in all patients. DCM patients with standard deviation of normal to normal RR intervals calculated over the 24 hour period (SDNN) < 50 ms had a significantly lower survival rate free of progressive heart failure than those with SDNN > 50 ms (P = 0.0002, at 12 months; P = 0.0001, during overall follow up). Stepwise multiple regression analysis showed that SDNN < 50 ms identified, independently of other clinical variables, patients who were at increased risk of developing progressive heart failure (P = 0.0004). CONCLUSIONS: HRV is reduced in patients with DCM and related to disease severity. HRV is clinically useful as an early non-invasive marker of DCM deterioration. PMID:9068391

Use of Hundreds of Electrocardiograhpic Biomarkers for Prediction of Mortality in Post-Menopausal Women: The Women’s Health Initiative

PubMed Central

Gorodeski, Eiran Z.; Ishwaran, Hemant; Kogalur, Udaya B.; Blackstone, Eugene H.; Hsich, Eileen; Zhang, Zhu-ming; Vitolins, Mara Z.; Manson, JoAnn E.; Curb, J. David; Martin, Lisa W.; Prineas, Ronald J.; Lauer, Michael S.

2013-01-01

Background Simultaneous contribution of hundreds of electrocardiographic biomarkers to prediction of long-term mortality in post-menopausal women with clinically normal resting electrocardiograms (ECGs) is unknown. Methods and Results We analyzed ECGs and all-cause mortality in 33,144 women enrolled in Women’s Health Initiative trials, who were without baseline cardiovascular disease or cancer, and had normal ECGs by Minnesota and Novacode criteria. Four hundred and seventy seven ECG biomarkers, encompassing global and individual ECG findings, were measured using computer algorithms. During a median follow-up of 8.1 years (range for survivors 0.5–11.2 years), 1,229 women died. For analyses cohort was randomly split into derivation (n=22,096, deaths=819) and validation (n=11,048, deaths=410) subsets. ECG biomarkers, demographic, and clinical characteristics were simultaneously analyzed using both traditional Cox regression and Random Survival Forest (RSF), a novel algorithmic machine-learning approach. Regression modeling failed to converge. RSF variable selection yielded 20 variables that were independently predictive of long-term mortality, 14 of which were ECG biomarkers related to autonomic tone, atrial conduction, and ventricular depolarization and repolarization. Conclusions We identified 14 ECG biomarkers from amongst hundreds that were associated with long-term prognosis using a novel random forest variable selection methodology. These were related to autonomic tone, atrial conduction, ventricular depolarization, and ventricular repolarization. Quantitative ECG biomarkers have prognostic importance, and may be markers of subclinical disease in apparently healthy post-menopausal women. PMID:21862719

Four-dimensional ultrasonography of the fetal heart using color Doppler spatiotemporal image correlation.

PubMed

Gonçalves, Luís F; Romero, Roberto; Espinoza, Jimmy; Lee, Wesley; Treadwell, Marjorie; Chintala, Kavitha; Brandl, Helmut; Chaiworapongsa, Tinnakorn

2004-04-01

To describe clinical and research applications of 4-dimensional imaging of the fetal heart using color Doppler spatiotemporal image correlation. Forty-four volume data sets were acquired by color Doppler spatiotemporal image correlation. Seven subjects were examined: 4 fetuses without abnormalities, 1 fetus with ventriculomegaly and a hypoplastic cerebellum but normal cardiac anatomy, and 2 fetuses with cardiac anomalies detected by fetal echocardiography (1 case of a ventricular septal defect associated with trisomy 21 and 1 case of a double-inlet right ventricle with a 46,XX karyotype). The median gestational age at the time of examination was 21 3/7 weeks (range, 19 5/7-34 0/7 weeks). Volume data sets were reviewed offline by multiplanar display and volume-rendering methods. Representative images and online video clips illustrating the diagnostic potential of this technology are presented. Color Doppler spatiotemporal image correlation allowed multiplanar visualization of ventricular septal defects, multiplanar display and volume rendering of tricuspid regurgitation, volume rendering of the outflow tracts by color and power Doppler ultrasonography (both in a normal case and in a case of a double-inlet right ventricle with a double-outlet right ventricle), and visualization of venous streams at the level of the foramen ovale. Color Doppler spatiotemporal image correlation has the potential to simplify visualization of the outflow tracts and improve the evaluation of the location and extent of ventricular septal defects. Other applications include 3-dimensional evaluation of regurgitation jets and venous streams at the level of the foramen ovale.

The role of cerebral hyperperfusion in postoperative neurologic dysfunction after left ventricular assist device implantation for end-stage heart failure.

PubMed

Lietz, Katherine; Brown, Kevin; Ali, Syed S; Colvin-Adams, Monica; Boyle, Andrew J; Anderson, David; Weinberg, Alan D; Miller, Leslie W; Park, Soon; John, Ranjit; Lazar, Ronald M

2009-04-01

Cerebral hyperperfusion is a life-threatening syndrome that can occur in patients with chronically hypoperfused cerebral vasculature whose normal cerebral circulation was re-established after carotid endarterectomy or angioplasty. We sought to determine whether the abrupt restoration of perfusion to the brain after left ventricular assist device (LVAD) implantation produced similar syndromes. We studied the role of increased systemic flow after LVAD implantation on neurologic dysfunction in 69 consecutive HeartMate XVE LVAD (Thoratec, Pleasanton, Calif) recipients from October 2001 through June 2006. Neurologic dysfunction was defined as postoperative permanent or transient central change in neurologic status, including confusion, focal neurologic deficits, visual changes, seizures, or coma for more than 24 hours within 30 days after LVAD implantation. We found that 19 (27.5%) patients had neurologic dysfunction, including encephalopathy (n = 11), coma (n = 3), and other complications (n = 5). The multivariate analysis showed that an increase in cardiac index from the preoperative baseline value (relative risk, 1.33 per 25% cardiac index increase; P = .01) and a previous coronary bypass operation (relative risk, 4.53; P = .02) were the only independent predictors of neurologic dysfunction. Reduction of left ventricular assist device flow in 16 of the 19 symptomatic patients led to improvement of symptoms in 14 (87%) patients. Our findings showed that normal flow might overwhelm cerebral autoregulation in patients with severe heart failure, suggesting that cerebral hyperperfusion is possible in recipients of mechanical circulatory support with neurologic dysfunction.

Defining the molecular signatures of human right heart failure.

PubMed

Williams, Jordan L; Cavus, Omer; Loccoh, Emefah C; Adelman, Sara; Daugherty, John C; Smith, Sakima A; Canan, Benjamin; Janssen, Paul M L; Koenig, Sara; Kline, Crystal F; Mohler, Peter J; Bradley, Elisa A

2018-03-01

Right ventricular failure (RVF) varies significantly from the more common left ventricular failure (LVF). This study was undertaken to determine potential molecular pathways that are important in human right ventricular (RV) function and may mediate RVF. We analyzed mRNA of human non-failing LV and RV samples and RVF samples from patients with pulmonary arterial hypertension (PAH), and post-LVAD implantation. We then performed transcript analysis to determine differential expression of genes in the human heart samples. Immunoblot quantification was performed followed by analysis of non-failing and failing phenotypes. Inflammatory pathways were more commonly dysregulated in RV tissue (both non-failing and failing phenotypes). In non-failing human RV tissue we found important differences in expression of FIGF, TRAPPAC, and CTGF suggesting that regulation of normal RV and LV function are not the same. In failing RV tissue, FBN2, CTGF, SMOC2, and TRAPP6AC were differentially expressed, and are potential targets for further study. This work provides some of the first analyses of the molecular heterogeneity between human RV and LV tissue, as well as key differences in human disease (RVF secondary to pulmonary hypertension and LVAD mediated RVF). Our transcriptional data indicated that inflammatory pathways may be more important in RV tissue, and changes in FIGF and CTGF supported this hypothesis. In PAH RV failure samples, upregulation of FBN2 and CTGF further reinforced the potential significance that altered remodeling and inflammation play in normal RV function and failure. Copyright © 2018 Elsevier Inc. All rights reserved.

QishenYiqi Dripping Pill Improves Heart Failure by Up-Regulation of β2-Adrenergic Receptor Expression.

PubMed

Sun, Junfeng; Qian, Hua; Li, Xiaoguang; Tang, Xianling

2017-03-01

QishenYiqi Dripping Pill (QYDP) is a Chinese herbal medicine that originally was used for the treatment of coronary artery disease. Recently, QYDP was used as a complementary treatment for heart failure (HF) in China. An HF rat model was used to clarify the possible therapeutic effects of QYDP on HF. The HF rats were allocated to two groups, HF and HF+QYDP, while normal rats served as a negative control. Cardiac functions were evaluated echocardiographically and hemodynamically. Cardiac apoptosis and the expression of β-adrenergic receptors were also investigated. Compared to the HF group, rats in the HF+QYDP group had a significantly higher fraction shortening (p<0.05), ejection fraction (p<0.05), left ventricular systolic pressure (p<0.05), maximum positive derivatives of left ventricular pressure (p<0.05), maximum negative derivatives of left ventricular pressure (p<0.05), and β2-adrenergic receptor expression (p<0.05), and lower left ventricular end-diastolic pressure (p<0.05) and apoptotic index (p<0.05). The study results indicated that QYDP could efficiently improve HF, possibly by an inhibition of cardiac apoptosis via the β2-adrenergic receptor signaling pathway. Hence, QYDP might be a promising candidate drug for HF therapy.

Correlation between Serum Calcineurin Activity and Left Ventricular Hypertrophy in Hypertensive Patients and Its Clinical Significance.

PubMed

Cao, Jia-Li; Yang, Yu-Qing; Nabeel, Dookhun Muhammad; Sun, Ya-Li; Zou, Hua-Yi-Yang; Kong, Xiang-Qing; Lu, Xin-Zheng

The aim of this study is to investigate the correlation between calcineurin (CaN) and hypertension with left ventricular hypertrophy (HLVH) and to evaluate its potential clinical significance. The study involved 160 patients diagnosed with hypertension and 42 controls. Based on the exclusion criteria, 42 were not eligible for this study. The remaining 118 hypertensive patients were categorized into 2 subgroups based on left ventricular mass index and relative ventricular wall thickness: a normal model subgroup with hypertension (HNM) and an HLVH subgroup. Serum CaN levels were determined by enzyme-linked immunosorbent assay, while serum CaN activity was determined by malachite green colorimetric assay. Among the HNM and HLVH subgroups, a positive correlation was demonstrated between serum CaN activity, but not serum CaN level, and HLVH. Moreover, the HLVH subgroup displayed a remarkable increase in the levels of brain natriuretic peptide, cystatin C, urinary albumin/creatinine ratio, and left atrium diameter compared to the HNM subgroup and controls. There was a positive correlation between serum CaN activity and LVH in hypertensive patients. Activated CaN could play an important role in the pathophysiologic mechanism of HLVH. Serum CaN activity could be a clinically useful diagnostic and prognostic biomarker for LVH. © 2018 S. Karger AG, Basel.

Salt intake during pregnancy alters offspring's myocardial structure.

PubMed

Alves-Rodrigues, E N; Veras, M M; Rosa, K T; de Castro, I; Furukawa, L N S; Oliveira, I B; Souza, R M; Heimann, J C

2013-05-01

To evaluate the effects of low or high salt intake during pregnancy on left ventricle of adult male offspring. Low- (LS, 0.15%), normal- (NS, 1.3%) or high-salt (HS, 8% NaCl) diet was given to Wistar rats during pregnancy. During lactation all dams received NS as well as the offspring after weaning. To evaluate cardiac response to salt overload, 50% of each offspring group was fed a high-salt (hs, 4% NaCl) diet from the 21st to the 36th week of age (LShs, NShs, HShs). The remaining 50% was maintained on NS (LSns, NSns and HSns). Echocardiography was done at 20 and 30 weeks of age. Mean blood pressure (MBP), histology and left ventricular angiotensin II content (AII) were analyzed at 36 weeks of age. Interventricular septum, left ventricular posterior wall and relative wall thickness increased from the 20th to the 30th week of age only in HShs, cardiomyocyte mean volume was higher in HShs compared to NShs, LShs and HSns. AII and left ventricular fibrosis were not different among groups. HS during pregnancy programs adult male offspring to a blood pressure and angiotensin II independent concentric left ventricular hypertrophy, with no fibrosis, in response to a chronic high-salt intake. Copyright © 2011 Elsevier B.V. All rights reserved.

Simultaneous transcatheter therapy for perimembranous ventricular septal defect combined with patent ductus arteriosus.

PubMed

Wang, Qiguang; Zhu, Xianyang; Duanzhen, Zhang; Zhang, Po; Chen, Huoyuan; Han, Xiumin; Sheng, Xiaotang; Meng, Lili

2017-06-01

This study aims to assess the clinical efficiency and safety of simultaneous transcatheter interventional treatment for perimembranous ventricular septal defect (pmVSD) combined with patent ductus arteriosus (PDA). Twenty-five patients with pmVSD and PDA treated with simultaneous transcatheter interventions from April 2004 to December 2015 were included in this study. The mean age was 9.80 ± 8.14 years and the mean weight was 29.76 ± 14.82 Kg. Transthoracic echocardiography (TTE) and angiography were performed immediately after the procedure. Patients were re-examined by electrocardiogram, X-ray, and TTE at 2 days, 1 month, 3 months, and 6 months postoperatively. The interventional procedure was successfully performed in all 25 patients. No intraoperative complication was noted. TTE examination of the VSD and PDA immediately after the procedure showed no residual shunt and the occluder was well positioned. Among these patients, four patients showed electrocardiogram changes after the procedure that resolved after drug therapy. The cardiothoracic ratio, left atrial diameter, left ventricular end-systolic diameter, and left ventricular end-diastolic diameter recovered to normal in most patients at 6 months postoperatively. Simultaneously transcatheter interventional therapy is a safe and effective method for pmVSD combined with PDA. © 2017 Wiley Periodicals, Inc.

Ventricular Septal Perforation after Biventricular Takotsubo Cardiomyopathy Successfully Repaired with an Amplatzer Device: First Report in the Literature.

PubMed

Rodríguez, Alfredo E; Fernandez-Pereira, Carlos; Mieres, Juan; Ascarrunz, Diego; Gabe, Eduardo; Rodríguez-Granillo, Alfredo Matías; Frattini, Romina; Stuzbach, Pablo

2016-01-01

A 79-year-old female was admitted with sudden onset dyspnea, mild oppressive chest pain, and severe anxiety disorder. Patient had history of hypertension, dyslipidemia, smoking, and chronic obstructive pulmonary disease. On admission blood pressure was 160/90 and heart rate was 130 bpm. Transthoracic echocardiography (TE) and contrast tomography showed a thin septum with an abnormal left and right ventricular contraction with an "apical ballooning" pattern and mild increase of cardiac enzymes. At the 4th day of admission, the patient presented symptoms and signs of congestive heart failure and developed cardiogenic shock. EKG showed an inversion of T waves in all precordial leads. In a new TE, a ventricular septal perforation (VSP) in the apical portion of the septum was seen. Coronary angiogram showed angiographically "normal" coronary arteries. With a diagnosis of VSP in takotsubo cardiomyopathy, a percutaneous procedure to repair the VSP was performed 11 days after admission. The VSP was closed with an Amplatzer device. TE performed 24 hours after showed significant improvement of ventricular function and good apposition of the Amplatzer device. Three days later she was discharged from the hospital. To our knowledge, this is the first reported case of a VSP in a TCM repaired percutaneously with an occluder device.

Impact of Hypokalemia on Electromechanical Window, Excitation Wavelength and Repolarization Gradients in Guinea-Pig and Rabbit Hearts

PubMed Central

Osadchii, Oleg E.

2014-01-01

Normal hearts exhibit a positive time difference between the end of ventricular contraction and the end of QT interval, which is referred to as the electromechanical (EM) window. Drug-induced prolongation of repolarization may lead to the negative EM window, which was proposed to be a novel proarrhythmic marker. This study examined whether abnormal changes in the EM window may account for arrhythmogenic effects produced by hypokalemia. Left ventricular pressure, electrocardiogram, and epicardial monophasic action potentials were recorded in perfused hearts from guinea-pig and rabbit. Hypokalemia (2.5 mM K+) was found to prolong repolarization, reduce the EM window, and promote tachyarrhythmia. Nevertheless, during both regular pacing and extrasystolic excitation, the increased QT interval invariably remained shorter than the duration of mechanical systole, thus yielding positive EM window values. Hypokalemia-induced arrhythmogenicity was associated with slowed ventricular conduction, and shortened effective refractory periods, which translated to a reduced excitation wavelength index. Hypokalemia also evoked non-uniform prolongation of action potential duration in distinct epicardial regions, which resulted in increased spatial variability in the repolarization time. These findings suggest that arrhythmogenic effects of hypokalemia are not accounted for by the negative EM window, and are rather attributed to abnormal changes in ventricular conduction times, refractoriness, excitation wavelength, and spatial repolarization gradients. PMID:25141124

Early identification of amyloid heart disease by technetium-99m-pyrophosphate scintigraphy: a study with familial amyloid polyneuropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hongo, M.; Hirayama, J.; Fujii, T.

1987-03-01

To determine whether technetium-99m-pyrophosphate (Tc-99m-PYP) scanning or two-dimensional echocardiography can detect amyloid heart disease in an earlier stage of familial amyloid polyneuropathy, 15 patients were examined. Although 10 of the 15 patients had no clinical evidence of congestive heart failure, as well as normal ventricular wall thickness and normal values for left ventricular systolic function, five (50%) of them showed mild or moderate myocardial uptake. On the other hand, none had characteristic highly refractile myocardial echoes on the two-dimensional echocardiographic images (p less than 0.01), and values for diastolic function were reduced in four of the five and normal inmore » the remaining one. In 85 control subjects, diffuse positive pyrophosphate scans of the heart were found in four (5%) of them (three with dilated cardiomyopathy and one with sarcoidosis), and highly refractile granular sparkling echoes were observed in nine (11%) (five with hypertrophic cardiomyopathy, three with aortic stenosis, and one with hypereosinophilic syndrome). We conclude that Tc-99m-PYP scanning is a more sensitive and specific method and may have the potential ability to detect amyloid heart disease in the earlier stage of familial amyloid polyneuropathy than two-dimensional echocardiography.« less

Spatial resolution of pace mapping of idiopathic ventricular tachycardia/ectopy originating in the right ventricular outflow tract.

PubMed

Bogun, Frank; Taj, Majid; Ting, Michael; Kim, Hyungjin Myra; Reich, Stephen; Good, Eric; Jongnarangsin, Krit; Chugh, Aman; Pelosi, Frank; Oral, Hakan; Morady, Fred

2008-03-01

Pace mapping has been used to identify the site of origin of focal ventricular arrhythmias. The spatial resolution of pace mapping has not been adequately quantified using currently available three-dimensional mapping systems. The purpose of this study was to determine the spatial resolution of pace mapping in patients with idiopathic ventricular tachycardia or premature ventricular contractions originating in the right ventricular outflow tract. In 16 patients with idiopathic ventricular tachycardia/ectopy from the right ventricular outflow tract, comparisons and classifications of pace maps were performed by two observers (good pace map: match >10/12 leads; inadequate pace map: match < or =10/12 leads) and a customized MATLAB 6.0 program (assessing correlation coefficient and normalized root mean square of the difference (nRMSd) between test and template signals). With an electroanatomic mapping system, the correlation coefficient of each pace map was correlated with the distance between the pacing site and the effective ablation site. The endocardial area within the 10-ms activation isochrone was measured. The ablation procedure was effective in all patients. Sites with good pace maps had a higher correlation coefficient and lower nRMSd than sites with inadequate pace maps (correlation coefficient: 0.96 +/- 0.03 vs 0.76 +/- 0.18, P <.0001; nRMSd: 0.41 +/- 0.16 vs 0.89 +/- 0.39, P <.0001). Using receiver operating characteristic curves, appropriate cutoff values were >0.94 for correlation coefficient (sensitivity 81%, specificity 89%) and < or =0.54 for nRMSd (sensitivity 76%, specificity 80%). Good pace maps were located a mean of 7.3 +/- 5.0 mm from the effective ablation site and had a mean activation time of -24 +/- 7 ms. However, in 3 (18%) of 16 patients, the best pace map was inadequate at the effective ablation site, with an endocardial activation time at these sites of -25 +/- 12 ms. Pace maps with correlation coefficient > or =0.94 were confined to an area of 1.8 +/- 0.6 cm2. The 10-ms isochrone measured 1.2 +/- 0.7 cm2. The spatial resolution of a good pace map for targeting ventricular tachycardia/ectopy is 1.8 cm2 in the right ventricular outflow tract and therefore is inferior to the spatial resolution of activation mapping as assessed by isochronal activation. In approximately 20% of patients, pace mapping is unreliable in identifying the site of origin, possibly due a deeper site of origin and preferential conduction via fibers connecting the focus to the endocardial surface.

Effects of right ventricular hemodynamic burden on intraventricular flow in tetralogy of fallot: an echocardiographic contrast particle imaging velocimetry study.

PubMed

Kutty, Shelby; Li, Ling; Danford, David A; Houle, Helene; Datta, Saurabh; Mancina, Joel; Xiao, Yunbin; Pedrizzetti, Gianni; Porter, Thomas R

2014-12-01

The purpose of this investigation was to test the hypothesis that flow patterns in the right ventricle are abnormal in patients with repaired tetralogy of Fallot (TOF). High-resolution echocardiographic contrast particle imaging velocimetry was used to investigate rotation intensity and kinetic energy dissipation of right ventricular (RV) flow in patients with TOF compared with normal controls. Forty-one subjects (16 with repaired TOF and varying degrees of RV dilation and 25 normal controls) underwent prospective contrast imaging using the lipid-encapsulated microbubble (Definity) on Sequoia systems. A mechanical index of 0.4, three-beat high-frame rate (>60 Hz) captures, and harmonic frequencies were used. Rotation intensity and kinetic energy dissipation of flow in the right and left ventricles were studied (Hyperflow). Ventricular volumes and ejection fractions in all subjects were derived from same-day cardiac magnetic resonance (CMR). Measurable planar maps were obtained for the left ventricle in 14 patients and the right ventricle in 10 patients among those with TOF and for the left ventricle in 23 controls and the right ventricle in 21 controls. Compared with controls, the TOF group had higher RV indexed end-diastolic volumes (117.8 ± 25.5 vs 88 ± 15.4 mL/m(2), P < .001) and lower RV ejection fractions (44.6 ± 3.6% vs 51.8 ± 3.6%, P < .001). Steady-streaming (heartbeat-averaged) flow rotation intensities were higher in patients with TOF for the left ventricle (0.4 ± 0.13 vs 0.29 ± 0.08, P = .012) and the right ventricle (0.53 ± 0.15 vs 0.26 ± 0.12, P < .001), whereas kinetic energy dissipation in TOF ventricles was lower (for the left ventricle, 0.51 ± 0.29 vs 1.52 ± 0.69, P < .001; for the right ventricle, 0.4 ± 0.24 vs 1.65 ± 0.91, P < .001). It is feasible to characterize RV and left ventricular flow parameters and planar maps in adolescents and adults with repaired TOF using echocardiographic contrast particle imaging velocimetry. Intraventricular flow patterns in the abnormal and/or enlarged right ventricle in patients with TOF differ from those in normal young adults. The rotation intensity and energy dissipation trends in this investigation suggest that they may be quantitative markers of RV and left ventricular compliance abnormalities in patients with repaired TOF. This hypothesis merits further investigation. Copyright © 2014 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Comparison of plasma B-type natriuretic peptide levels in single ventricle patients with systemic ventricle heart failure versus isolated cavopulmonary failure.

PubMed

Law, Yuk Ming; Ettedgui, Jose; Beerman, Lee; Maisel, Alan; Tofovic, Stevan

2006-08-15

The measurement of plasma B-type natriuretic peptide (BNP) has emerged as a useful biomarker of heart failure in patients with cardiomyopathy. The pathophysiology of heart failure in single ventricle (SV) circulation may be distinct from that of cardiomyopathies. A distinct pattern of BNP elevation in heart failure in the SV population was hypothesized: it is elevated in heart failure secondary to ventricular dysfunction but not in isolated cavopulmonary failure. BNP was measured prospectively in SV patients at catheterization (n = 22) and when assessing for heart failure (n = 11) (7 normal controls). Of 33 SV subjects (median age 62 months), 13 had aortopulmonary connections and 20 had cavopulmonary connections. Median and mean +/- SD BNP levels by shunt type were 184 and 754 +/- 1,086 pg/ml in the patients with aortopulmonary connections, 38 and 169 +/- 251 pg/ml in the patients with cavopulmonary connections, and 10 and 11 +/- 5 pg/ml in normal controls, respectively (p = 0.004). Median systemic ventricular end-diastolic pressure (8mm Hg, R = 0.45), mean pulmonary artery pressure (14.5 mm Hg, R = 0.62), and mean right atrial pressure (6.5 mm Hg, R = 0.54) were correlated with plasma BNP. SV subjects with symptomatic heart failure from dysfunctional systemic ventricles had median and mean +/- SD BNP levels of 378 and 714 +/- 912 pg/ml (n = 18) compared with patients with isolated failed Glenn or Fontan connections (19 and 23 +/- 16 pg/ml [n = 7, p = 0.001]) and those with no heart failure (22 and 22 +/- 12 pg/ml [n = 8, p = 0.001]). Excluding the group with cavopulmonary failure, the severity of heart failure from systemic ventricular dysfunction was associated with plasma BNP. In conclusion, plasma BNP is elevated in SV patients with systemic ventricular or left-sided cardiac failure. BNP is not elevated in patients missing a pulmonary ventricle with isolated cavopulmonary failure.

Impact of severe left ventricular dysfunction on in-hospital and mid-term outcomes of Chinese patients undergoing first isolated off-pump coronary artery bypass grafting.

PubMed

Ji, Qiang; Xia, Li Min; Shi, Yun Qing; Ma, Run Hua; Shen, Jin Qiang; Ding, Wen Jun; Wang, Chun Sheng

2017-10-10

Few studies focused on evaluating the impacts of preoperative severe left ventricular dysfunction on clinical outcomes of patients undergoing off-pump coronary artery bypass grafting surgery (OPCAB). This single center retrospective study aimed to evaluate the impacts of severe left ventricular dysfunction on in-hospital and mid-term clinical outcomes of Chinese patients undergoing first, scheduled, and isolated OPCAB surgery. From January 2010 to December 2014, 2032 eligible patients were included in this study and were divided into 3 groups: a severe group (patients with preoperative left ventricular ejection fraction (LVEF) of ≤35%, n = 128), an impaired group (patients with preoperative LVEF of 36-50%, n = 680), and a normal group (patients with preoperative LVEF of >50%, n = 1224). In-hospital and follow-up clinical outcomes were investigated and compared. Patients in the severe group compared to the other 2 groups had higher in-hospital mortality and higher incidences of low cardiac output and prolonged ventilation. Kaplan-Meier curves showed a similar cumulative follow-up survival between the severe group and the impaired group (χ 2  = 1.980, Log-rank p = 0.159) and between the severe group and the normal group (χ 2  = 2.701, Log-rank p = 0.102). Multivariate Cox regression indicated that grouping was not a significant variable related to mid-term all-cause mortality. No significant difference was found in the rate of repeat revascularization between the severe group (2.4%) and the other 2 groups. Patients with preoperative LVEF of ≤35% compared to preoperative LVEF of >35% increased the risk of in-hospital death and incidences of postoperative low cardiac output and prolonged ventilation, but shared similar mid-term all-cause mortality and repeat revascularization after OPCAB surgery.

Patients with left bundle branch block and left axis deviation show a specific left ventricular asynchrony pattern: Implications for left ventricular lead placement during CRT implantation.

PubMed

Sciarra, Luigi; Golia, Paolo; Palamà, Zefferino; Scarà, Antonio; De Ruvo, Ermenegildo; Borrelli, Alessio; Martino, Anna Maria; Minati, Monia; Fagagnini, Alessandro; Tota, Claudia; De Luca, Lucia; Grieco, Domenico; Delise, Pietro; Calò, Leonardo

Left bundle branch block (LBBB) and left axis deviation (LAD) patients may have poor response to resynchronization therapy (CRT). We sought to assess if LBBB and LAD patients show a specific pattern of mechanical asynchrony. CRT candidates with non-ischemic cardiomyopathy and LBBB were categorized as having normal QRS axis (within -30° and +90°) or LAD (within -30° and -90°). Patients underwent tissue Doppler imaging (TDI) to measure time interval between onset of QRS complex and peak systolic velocity in ejection period (Q-peak) at basal segments of septal, inferior, lateral and anterior walls, as expression of local timing of mechanical activation. Thirty patients (mean age 70.6years; 19 males) were included. Mean left ventricular ejection fraction was 0.28±0.06. Mean QRS duration was 172.5±13.9ms. Fifteen patients showed LBBB with LAD (QRS duration 173±14; EF 0.27±0.06). The other 15 patients had LBBB with a normal QRS axis (QRS duration 172±14; EF 0.29±0.05). Among patients with LAD, Q-peak interval was significantly longer at the anterior wall in comparison to each other walls (septal 201±46ms, inferior 242±58ms, lateral 267±45ms, anterior 302±50ms; p<0.0001). Conversely, in patients without LAD Q-peak interval was longer at lateral wall, when compared to each other (septal 228±65ms, inferior 250±64ms, lateral 328±98ms, anterior 291±86ms; p<0.0001). Patients with heart failure, presenting LBBB and LAD, show a specific pattern of ventricular asynchrony, with latest activation at anterior wall. This finding could affect target vessel selection during CRT procedures in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment and significance of left ventricular mass by cardiovascular magnetic resonance in hypertrophic cardiomyopathy.

PubMed

Olivotto, Iacopo; Maron, Martin S; Autore, Camillo; Lesser, John R; Rega, Luigi; Casolo, Giancarlo; De Santis, Marcello; Quarta, Giovanni; Nistri, Stefano; Cecchi, Franco; Salton, Carol J; Udelson, James E; Manning, Warren J; Maron, Barry J

2008-08-12

Our aim was to assess the distribution and clinical significance of left ventricular (LV) mass in patients with hypertrophic cardiomyopathy (HCM). Hypertrophic cardiomyopathy is defined echocardiographically by unexplained left ventricular wall thickening. Left ventricular mass, quantifiable by modern cardiovascular magnetic resonance techniques, has not been systematically assessed in this disease. In 264 HCM patients (age 43 +/- 18 years; 75% men), LV mass by cardiovascular magnetic resonance was measured, indexed by body surface area, and compared with that in 606 healthy control subjects. The LV mass index in HCM patients significantly exceeded that of control subjects (104 +/- 40 g/m(2) vs. 61 +/- 10 g/m(2) in men and 89 +/- 33 g/m(2) vs. 47 +/- 7 g/m(2) in women; both p < 0.0001). However, values were within the normal range (< or = mean +2 SDs for control subjects) in 56 patients (21%), and only mildly increased (mean +2 to 3 SDs) in 18 (16%). The LV mass index showed a modest relationship to maximal LV thickness (r(2) = 0.38; p < 0.001), and was greater in men (104 +/- 40 g/m(2) vs. 89 +/- 33 g/m(2) in women; p < 0.001) and in patients with resting outflow obstruction (121 +/- 43 g/m(2) vs. 96 +/- 37 g/m(2) in nonobstructives; p < 0.001). During a 2.6 +/- 0.7-year follow-up, markedly increased LV mass index proved more sensitive in predicting outcome (100%, with 39% specificity), whereas maximal wall thickness >30 mm was more specific (90%, with 41% sensitivity). In distinction to prior perceptions, LV mass index was normal in about 20% of patients with definite HCM phenotype. Therefore, increased LV mass is not a requirement for establishing the clinical diagnosis of HCM. The LV mass correlated weakly with maximal wall thickness, and proved more sensitive in predicting outcome.

Zinc Levels in Left Ventricular Hypertrophy.

PubMed

Huang, Lei; Teng, Tianming; Bian, Bo; Yao, Wei; Yu, Xuefang; Wang, Zhuoqun; Xu, Zhelong; Sun, Yuemin

2017-03-01

Zinc is one of the most important trace elements in the body and zinc homeostasis plays a critical role in maintaining cellular structure and function. Zinc dyshomeostasis can lead to many diseases, such as cardiovascular disease. Our aim was to investigate whether there is a relationship between zinc and left ventricular hypertrophy (LVH). A total of 519 patients was enrolled and their serum zinc levels were measured in this study. We performed analyses on the relationship between zinc levels and LVH and the four LV geometry pattern patients: normal LV geometry, concentric remodeling, eccentric LVH, and concentric LVH. We performed further linear and multiple regression analyses to confirm the relationship between zinc and left ventricular mass (LVM), left ventricular mass index (LVMI), and relative wall thickness (RWT). Our data showed that zinc levels were 710.2 ± 243.0 μg/L in the control group and were 641.9 ± 215.2 μg/L in LVH patients. We observed that zinc levels were 715 ± 243.5 μg/L, 694.2 ± 242.7 μg/L, 643.7 ± 225.0 μg/L, and 638.7 ± 197.0 μg/L in normal LV geometry, concentric remodeling, eccentric LVH, and concentric LVH patients, respectively. We further found that there was a significant inverse linear relationship between zinc and LVM (p = 0.001) and LVMI (p = 0.000) but did not show a significant relationship with RWT (p = 0.561). Multiple regression analyses confirmed that the linear relationship between zinc and LVM and LVMI remained inversely significant. The present study revealed that serum zinc levels were significantly decreased in the LVH patients, especially in the eccentric LVH and concentric LVH patients. Furthermore, zinc levels were significantly inversely correlated with LVM and LVMI.

Flow void of cerebrospinal fluid in idiopathic normal pressure hydrocephalus of the elderly: can it predict outcome after shunting?

PubMed

Krauss, J K; Regel, J P; Vach, W; Jüngling, F D; Droste, D W; Wakhloo, A K

1997-01-01

We investigate the predictive value of cerebrospinal fluid (CSF) flow void on outcome after shunting in a prospective series of patients with idiopathic normal pressure hydrocephalus (NPH). The degree and extension of CSF flow void were examined on T2-weighted magnetic resonance imaging scans of 37 elderly patients with idiopathic NPH who underwent subsequent shunting. The degree of flow void was assessed in comparison with the signal of large cerebral arteries. The extension was evaluated via the calculation of sum scores for the occurrence of flow void in different locations of the ventricular system. Those parameters were not considered in the decision to perform shunting. CSF flow void in the aqueduct and the adjacent third and fourth ventricles of the 37 patients with idiopathic NPH was compared with that of 37 age-matched control patients. CSF flow void scores in patients with idiopathic NPH were investigated for correlations between postoperative outcome scores and ventricular width indices. No difference was found between the occurrence of aqueductal CSF flow void in patients with idiopathic NPH and the control group. A significant difference, however, was noted for the extension of the CSF flow void, which was greater in the NPH group. Postoperative improvement was found in 33 of 37 patients with idiopathic NPH at a mean follow-up of 15.6 months. Only small, statistically not significant correlations were found between CSF flow void and postoperative outcome. Flow void sum scores, however, correlated significantly with ventricular width indices. The degree and extension of CSF flow void on T2-weighted magnetic resonance imaging scans have little predictive value for outcome after shunting in patients with idiopathic NPH. The greater extension of the CSF flow void in patients with NPH is most likely related to increased ventricular width. It is not useful to consider CSF flow void findings on conventional magnetic resonance imaging scans in making the decision to offer shunting in patients with idiopathic NPH.

The Prognostic Impact of the Evolution of RV Function in Idiopathic DCM.

PubMed

Merlo, Marco; Gobbo, Marco; Stolfo, Davide; Losurdo, Pasquale; Ramani, Federica; Barbati, Giulia; Pivetta, Alberto; Di Lenarda, Andrea; Anzini, Marco; Gigli, Marta; Pinamonti, Bruno; Sinagra, Gianfranco

2016-09-01

In this study, the authors analyzed the prognostic role of right ventricular systolic function (RVF) longitudinal trends in a large cohort of patients affected by dilated cardiomyopathy (DCM). RVF is a known prognostic predictor in DCM; however, whether RVF changes over time to better predict the long-term disease progression has not been investigated. From 1993 to 2008, we analyzed 512 patients with DCM (46 years of age [36 to 55 years of age], left ventricular ejection fraction 32% [25% to 41%]) with a potential follow-up of ≥72 months and available data at baseline and at least 1 pre-specified follow-up evaluation (i.e., 6, 24, 48, or 72 months). RV dysfunction was defined as RV fractional area change <35% at 2-dimensional echocardiography. The primary outcome measure was a composite of death or heart transplantation. At enrollment, 103 (20%) patients had RV dysfunction. During follow-up, 89 of them (86%, 17% of the overall cohort) normalized RVF at a median time of 6 months, whereas 38 of the remaining 409 patients with normal baseline RVF (9%; 7% of the overall population) exhibited a new-onset RV dysfunction (median time: 36 months). RVF normalization was significantly associated with subsequent left ventricular reverse remodeling that was observed at a median time of 24 months (odds ratio: 2.49; 95% confidence interval [CI]: 1.17 to 5.3; p = 0.018). At baseline multivariate analysis, RV dysfunction was independently associated with the primary outcome measure (hazard ratio: 1.71; 95% CI: 1.02 to 2.85; p = 0.0413). At time-dependent model, RVF revaluation over time maintained an independent predictive value (hazard ratio: 2.83; 95% CI: 1.57 to 5.11; p = 0.0006). Patients with DCM frequently present RV dysfunction at first evaluation. However, a complete RVF recovery is largely observed early after optimization of medical therapy and predates subsequent left ventricular reverse remodeling. Systematic revaluation of patients including RVF throughout regular follow-up conferred additive long-term prognostic value to the baseline evaluation. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

The effects of early antithyroid therapy for endogenous subclinical hyperthyroidism in clinical and heart abnormalities.

PubMed

Sgarbi, José A; Villaça, Fábio G; Garbeline, Benito; Villar, Heloísa E; Romaldini, João H

2003-04-01

Subclinical hyperthyroidism has been associated with harmful cardiac effects, but its treatment remains controversial. This study was designed to assess the cardiac effects of the normalization of serum TSH concentration in patients with endogenous subclinical hyperthyroidism. Ten patients (median age, 59 yr; range, 16-72 yr) with normal serum free T(4) and free T(3) concentration and a stable suppression of serum TSH levels were evaluated by Doppler-echocardiography, by standard and 24-h electrocardiography monitoring (Holter), and by the clinical Wayne index. Ten subjects, matched for age and sex, were used as controls. Patients were reevaluated 6 months after achieving stabilized euthyroidism by using methimazole with a median initial dose of 20 mg daily (10-30 mg daily). After reaching euthyroidism, we found a significant decrease in the heart rate (P = 0.008), the total number of beats during 24 h (P = 0.004), and the number of atrial (P = 0.002) and ventricular (P = 0.003) premature beats. Echocardiographical data resulted in a reduction of the left ventricular mass index (P = 0.009), interventricular septum thickness (P = 0.008), and left ventricular posterior wall thickness (P = 0.004) at diastole. Furthermore, the early diastolic peak flow velocity deceleration rate was significantly higher (P = 0.02) in the untreated patients compared with controls. The Wayne clinical index was higher in patients than in controls (P = 0.001) and decreased after treatment (P = 0.004). Serum TSH concentration returned to normal values after 2.5 months (range, 1.0-7.0 months) on methimazole therapy (0.05 vs. 1.42 mU/liter; P = 0.002). Serum free T(4) values were normal in patients before treatment but significantly decreased after reaching the euthyroidism (16.9 vs. 11.5 pmol/liter; P = 0.002). In contrast, serum free T(3) concentration did not differ among the groups. In conclusion, our findings support that early antithyroid therapy should be considered in patients with endogenous subclinical hyperthyroidism, where it is needed to prevent potential progression to a more advanced heart disease.

Non-Invasive Assessment of Susceptibility to Ventricular Arrhythmias During Simulated Microgravity

NASA Technical Reports Server (NTRS)

Cohen, Richard J.

1999-01-01

The Cardiovascular Alterations Team is currently conducting studies to determine what alterations in hemodynamic regulation result from sixteen days of simulated microgravity exposure in normal human subjects. In this project we make additional measurements on these same study subjects in order to determine whether there is an increase in susceptibility to ventricular arrhythmias resulting from simulated microgravity exposure. Numerous anecdotal and documented reports from the past 30 years suggest that the incidence of ventricular arrhythmias among astronauts is increased during space flight. For example, documented runs of ventricular tachycardia have been recorded from crew members of Skylab and Mir, there was much attention given by the lay press to Mir Commander Vasily Tslbliyev's complaints of heart rhythm irregularities in July of 1997, and cardiovascular mechanisms may have been causal in the recent death of an experimental primate shortly after return from space. In 1986, a Mir cosmonaut, Alexander Laveikin, was brought home and replaced with an alternate cosmonaut as a result of cardiac dysrhythmias that began during extravehicular activity. Furthermore, at a joint NASA/NSBRI workshop held in January 1998, cardiac arrhythmias were identified as the highest priority cardiovascular risk to a human Mars mission. Despite the evidence for the risk of a potentially lethal arrhythmia resulting from microgravity exposure, the effects of space flight and the associated physiologic stresses on cardiac conduction processes are not known, and an increase in cardiac susceptibility to arrhythmias has never been quantified. In this project, we are determining whether simulated space flight increases the risk of developing life-threatening heart rhythm disturbances such as sustained ventricular tachycardia (defined as ventricular tachycardia lasting at least 30 seconds or resulting in hemodynamic collapse) and ventricular fibrillation. We are obtaining measures of cardiac susceptibility to ventricular arrhythmias in subjects exposed to simulated space flight in the Human Studies Core protocol being conducted by the Cardiovascular Alterations Team, which involves sixteen days .of bed rest. In particular, we are applying a powerful new non-invasive technology, developed in Professor Cohen's laboratory at MIT for the quantitative assessment of the risk of life-threatening ventricular arrhythmias. This technology involves the measurement of microvolt levels of T wave alternans (TWA) during exercise stress, and was recently granted approval by the Food and Drug Administration to be used for the clinical evaluation of patients suspected to be at risk of ventricular arrhythmias. In addition, we are obtaining 24 hour Holter monitoring (to detect non-sustained ventricular tachycardia and to assess heart rate variability). We are also conducting protocols to obtain these same measures on a monthly basis for up to four months in subjects in the Bone Demineralization/calcium Metaboloism Team's long term bed rest study.

Prevalence, clinical and echocardiographic characteristics of various flow and gradient patterns in mild or moderate aortic stenosis with normal left ventricular ejection fraction.

PubMed

Tan, Yong-Qiang Benjamin; Ngiam, Jinghao Nicholas; Kong, William K F; Yeo, Tiong-Cheng; Poh, Kian-Keong

2016-10-15

Paradoxical low-flow aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) has only been described in severe AS. Controversy surrounds prognosis and management but no studies have reported this phenomenon in mild or moderate AS. We investigated the prevalence of flow and gradient patterns in this population, characterising their clinical and echocardiographic profile. Consecutive subjects (n=1362) with isolated AS: mild (n=462, aortic valve area≥1.5cm(2), 2.5m/s

Catheter ablation as a treatment of atrioventricular block.

PubMed

Tuohy, Stephen; Saliba, Walid; Pai, Manjunath; Tchou, Patrick

2018-01-01

Symptomatic second-degree atrioventricular (AV) block is typically treated by implantation of a pacemaker. An otherwise healthy AV conduction system can nevertheless develop AV block due to interference from junctional extrasystoles. When present with a high burden, these can produce debilitating symptoms from AV block despite an underlying normal AV node and His-Purkinje system properties. The purpose of this study was to describe a catheter ablation approach for alleviating symptomatic AV block due to a ventricular nodal pathway interfering with AV conduction. Common clinical monitoring techniques such as Holter and event recorders were used. Standard electrophysiological study techniques using multipolar recording and ablation catheters were utilized during procedures. A 55-year-old woman presented with highly symptomatic, high-burden second-degree AV block due to concealed and manifest junctional premature beats. Electrophysiological characteristics indicated interference of AV conduction due to a concealed ventricular nodal pathway as the cause of the AV block. The patient's AV nodal and His-Purkinje system conduction characteristics were otherwise normal. Radiofrequency catheter ablation of the pathway was successful in restoring normal AV conduction and eliminating her clinical symptoms. Pathways inserting into the AV junction can interfere with AV conduction. When present at a high burden, this type of AV block can be highly symptomatic. Catheter ablation techniques can be used to alleviate this type of AV block and restore normal AV conduction. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Comparison of superior vena caval and inferior vena caval access using a radioisotope technique during normal perfusion and cardiopulmonary resuscitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dalsey, W.C.; Barsan, W.G.; Joyce, S.M.

1984-10-01

Recent studies of thoracic pressure changes during external cardiopulmonary resuscitation (CPR) suggest that there may be a significant difference in the rate of delivery of intravenous drugs when they are administered through the extrathoracic inferior vena cava (IVC) rather than the intrathoracic superior vena cava (SVC). Comparison of delivery of a radionuclide given using superior and inferior vena caval access sites was made during normal blood flow and during CPR. Mean times from injection to peak emission count in each ventricle were determined. There were no significant differences between mean peak times for SVC or IVC routes during normal flowmore » or CPR. When peak times were corrected for variations in cardiac output, there were no significant differences between IVC and SVC peak times during normal flow. During CPR, however, mean left ventricular peak time, when corrected for cardiac output, was significantly shorter (P less than .05) when the SVC route was used. The mean time for the counts to reach half the ventricular peak was statistically shorter (P less than .05) in both ventricles with the SVC route during the low flow of CPR. This suggests that during CPR, increased drug dispersion may occur when drugs are infused by the IVC route and thus may modify the anticipated effect of the drug bolus. These results suggest that during CPR, both the cardiac output and the choice of venous access are important variables for drug delivery.« less

Idiopathic normal pressure hydrocephalus: theoretical concept of a spinal etiology.

PubMed

Hamlat, Abderrahmane; Abderrahmane, Hamlat; Sid-Ahmed, Seddik; Seddik, Sid-Ahmed; Adn, Mahmoudreza; Mahmoudreza, Adn; Askar, Brahim; Brahim, Askar; Pasqualini, Edouardo; Edouardo, Pasqualini

2006-01-01

Normal pressure hydrocephalus (NPH) is an adult syndrome characterised by a combination of gait disturbance, varying degrees of cognitive decline, urinary incontinence, ventricular enlargement and normal mean intracranial pressure. Since this syndrome was first described, its pathophysiology has been a matter of great debate, although it is now considered that NPH could be divided into two groups: cases with unknown etiology (idiopathic normal pressure hydrocephalus, or INPH) and those which develop from several known causes (such as trauma, meningitis or subarachnoid haemorrhage). The pathophysiology of INPH is still unclear and a matter of debate. In this manuscript, the current pathophysiological conditions of INPH are analysed and the authors put forward the theory that the disease is a dynamic syndrome which occurs in patients who have suffered a significant loss of spinal compliance over time. Consequently, intracranial pressure increases more during systole in INPH patients because it cannot be compensated for by the escape of CSF into the spinal canal as effectively, due to the reduced volume or lack of distension of the spinal canal. This leads to an increase in ventricular size and causes cumulative brain damage over a long period of time and accounts for the slow, progressive nature of NPH. The loss of spinal compliance with age is fundamental to the proposed theory which provides a theoretical justification for studying the spinal canal in INPH and investigating the relationship between the progressive narrowing of the spinal canal and the compensating ability of the craniospinal system.

Echocardiographic assessment by computer-assisted analysis of diastolic left ventricular function and hypertrophy in borderline or mild systemic hypertension.

PubMed

Papademetriou, V; Gottdiener, J S; Fletcher, R D; Freis, E D

1985-09-15

Systemic hypertension is a common cause of congestive heart failure. However, left ventricular (LV) systolic function remains normal for many years in patients with mild or moderate hypertension. In this study, high-quality M-mode echocardiograms were recorded in 7 patients with borderline hypertension, 14 patients with mild hypertension and 15 normal persons. Measures of systolic and diastolic LV function and the degree of LV hypertrophy were studied with the assistance of a tablet digitizer and dedicated microcomputer. Average blood pressure was 125 +/- 10/77 +/- 7 mm Hg in normal subjects, 146 +/- 18/92 +/- 2 mm Hg in patients with borderline hypertension and 150 +/- 11/102 +/- 4 in patients with mild hypertension. Indexes of systolic LV function were similar in all 3 groups. The peak rate of early relaxation of the LV posterior wall was significantly decreased in the group of patients with mild hypertension (4.7 vs 6.6 sec-1, p less than 0.01). The mitral valve closure rate was 150 +/- 32 mm/s in normal subjects, 119 +/- 35 mm/s in patients with borderline hypertension and 106 +/- 26 mm/s (p less than 0.001) in patients with mild hypertension. Mild LV hypertrophy was present in 6 of 7 patients with borderline and 13 of 14 patients with mild hypertension. The degree of hypertrophy and the level of blood pressure correlated poorly.(ABSTRACT TRUNCATED AT 250 WORDS)

Diprosopus with multiple craniofacial, musculoskeletal, and cardiac defects in a purebred Suffolk lamb.

PubMed

Kerr, Nancy J

2007-10-01

A stillborn Suffolk ewe lamb with 2 heads was found to have tarsal arthrogryposis, kypholordosis, craniorachischisis totalis, cheiloschisis, palatoschisis, deviation of the right maxilla, prognathia, patent ductus arteriosus, 3 ventricular septal defects, and 4 great vessels. The lamb was born twin to a normal lamb. No definitive etiology was established.

Cerebellar GABAergic progenitors adopt an external granule cell-like phenotype in the absence of Ptf1a transcription factor expression.

PubMed

Pascual, Marta; Abasolo, Ibane; Mingorance-Le Meur, Ana; Martínez, Albert; Del Rio, José A; Wright, Christopher V E; Real, Francisco X; Soriano, Eduardo

2007-03-20

We report in this study that, in the cerebellum, the pancreatic transcription factor Ptf1a is required for the specific generation of Purkinje cells (PCs) and interneurons. Moreover, granule cell progenitors in the external GCL (EGL) appear to be unaffected by deletion of Ptf1a. Cell lineage analysis in Ptf1a(Cre/Cre) mice was used to establish that, in the absence of Ptf1a expression, ventricular zone progenitors, normally fated to produce PCs and interneurons, aberrantly migrate to the EGL and express typical markers of these cells, such as Math1, Reelin, and Zic1/2. Furthermore, these cells have a fine structure typical of EGL progenitors, indicating that they adopt an EGL-like cell phenotype. These findings indicate that Ptf1a is necessary for the specification and normal production of PCs and cerebellar interneurons. Moreover, our results suggest that Ptf1a is also required for the suppression of the granule cell specification program in cerebellar ventricular zone precursors.

Stress-induced alteration of left ventricular eccentricity: An additional marker of multivessel CAD.

PubMed

Gimelli, Alessia; Liga, Riccardo; Giorgetti, Assuero; Casagranda, Mirta; Marzullo, Paolo

2017-03-28

Abnormal left ventricular (LV) eccentricity index (EI) is a marker of adverse cardiac remodeling. However, the interaction between stress-induced alterations of EI and major cardiac parameters has not been explored. We sought to evaluate the relationship between LV EI and coronary artery disease (CAD) burden in patients submitted to myocardial perfusion imaging (MPI). Three-hundred and forty-three patients underwent MPI and coronary angiography. LV ejection fraction (EF) and EI were computed from gated stress images as measures of stress-induced functional impairment. One-hundred and thirty-six (40%), 122 (35%), and 85 (25%) patients had normal coronary arteries, single-vessel CAD, and multivessel CAD, respectively. Post-stress EI was lower in patients with multivessel CAD than in those with normal coronary arteries and single-vessel CAD (P = 0.001). This relationship was confirmed only in patients undergoing exercise stress test, where a lower post-stress EI predicted the presence of multivessel CAD (P = 0.039). Post-stress alterations of LV EI on MPI may unmask the presence of multivessel CAD.

PubMed Central

Russo, Vincenzo; Papa, Andrea Antonio; Rago, Anna; D'Ambrosio, Paola; Cimmino, Giovanni; Palladino, Alberto; Nigro, Gerardo

2016-01-01

Sudden cardiac death in myotonic dystrophy type I (DM1) patients can be attributed to atrioventricular blocks as far as to the development of life-threatening arrhythmias which occur even in hearts with normal left ventricular systolic and diastolic function. Heterogeneity of ventricular repolarization is considered to provide an electrophysiological substrate for malignant arrhythmias. QTc dispersion (QTc-D), JTc dispersion (JTc-D) and transmural dispersion of repolarization (TDR) could reflect the physiological variability of regional and transmural ventricular repolarization. Aim of the present study was to investigate the heterogeneity of ventricular repolarization in patients with DM1 and preserved diastolic and systolic cardiac function. The study enrolled 50 DM1 patients (mean age 44 ± 5 years; M:F: 29:21) with preserved systolic and diastolic function of left ventricle among 247 DM1 patients followed at Cardiomyology and Medical Genetics of Second University of Naples, and 50 sexand age-matched healthy controls. The electrocardiographic parameters investigated were the following: Heart Rate, QRS duration, maximum and minimum QT and JT intervals, QTc- D, JTc-D and TDR. Compared to the controls, the DM1 group presented increased values of QTc-D (86.7 ± 40.1 vs 52.3 ± 11.9 ms; p = 0.03), JTc-D (78.6 ± 31.3 vs 61.3 ± 10.2 ms; p = 0.001) and TDR (101.6 ± 18.06 vs 90.1 ± 14.3 ms; p = 0.004) suggesting a significant increase in regional and transmural heterogeneity of the ventricular repolarization in these patients, despite a preserved systolic and diastolic cardiac function. PMID:28344440

Perspective: A Dynamics-Based Classification of Ventricular Arrhythmias

PubMed Central

Weiss, James N.; Garfinkel, Alan; Karagueuzian, Hrayr S.; Nguyen, Thao P.; Olcese, Riccardo; Chen, Peng-Sheng; Qu, Zhilin

2015-01-01

Despite key advances in the clinical management of life-threatening ventricular arrhythmias, culminating with the development of implantable cardioverter-defibrillators and catheter ablation techniques, pharmacologic/biologic therapeutics have lagged behind. The fundamental issue is that biological targets are molecular factors. Diseases, however, represent emergent properties at the scale of the organism that result from dynamic interactions between multiple constantly changing molecular factors. For a pharmacologic/biologic therapy to be effective, it must target the dynamic processes that underlie the disease. Here we propose a classification of ventricular arrhythmias that is based on our current understanding of the dynamics occurring at the subcellular, cellular, tissue and organism scales, which cause arrhythmias by simultaneously generating arrhythmia triggers and exacerbating tissue vulnerability. The goal is to create a framework that systematically links these key dynamic factors together with fixed factors (structural and electrophysiological heterogeneity) synergistically promoting electrical dispersion and increased arrhythmia risk to molecular factors that can serve as biological targets. We classify ventricular arrhythmias into three primary dynamic categories related generally to unstable Ca cycling, reduced repolarization, and excess repolarization, respectively. The clinical syndromes, arrhythmia mechanisms, dynamic factors and what is known about their molecular counterparts are discussed. Based on this framework, we propose a computational-experimental strategy for exploring the links between molecular factors, fixed factors and dynamic factors that underlie life-threatening ventricular arrhythmias. The ultimate objective is to facilitate drug development by creating an in silico platform to evaluate and predict comprehensively how molecular interventions affect not only a single targeted arrhythmia, but all primary arrhythmia dynamics categories as well as normal cardiac excitation-contraction coupling. PMID:25769672

Left atrial booster function in valvular heart disease.

PubMed

Heidenreich, F P; Shaver, J A; Thompson, M E; Leonard, J J

1970-09-01

This study was designed to assess atrial booster pump action in valvular heart disease and to dissect booster pump from reservoir-conduit functions. In five patients with aortic stenosis and six with mitral stenosis, sequential atrioventricular (A-V) pacing was instituted during the course of diagnostic cardiac catheterization. Continuous recording of valvular gradient allowed estimation of flow for each cardiac cycle by transposition of the Gorlin formula. Left ventricular ejection time and left ventricular stroke work in aortic stenosis or left ventricular mean systolic pressure in mitral stenosis were also determined. Control observations were recorded during sequential A-V pacing with well-timed atrial systole. Cardiac cycles were then produced with no atrial contraction but undisturbed atrial reservoir function by intermittently interrupting the atrial pacing stimulus during sequential A-V pacing. This intervention significantly reduced valvular gradient, flow, left ventricular ejection time, and left ventricular mean systolic pressure or stroke work. Cardiac cycles were then produced with atrial booster action eliminated by instituting synchronous A-V pacing. The resultant simultaneous contraction of the atrium and ventricle not only eliminated effective atrial systole but also placed atrial systole during the normal period of atrial reservoir function. This also significantly reduced all the hemodynamic measurements. However, comparison of the magnitude of change from these two different pacing interventions showed no greater impairment of hemodynamic state when both booster pump action and reservoir function were impaired than when booster pump action alone was impaired. The study confirms the potential benefit of well placed atrial booster pump action in valvular heart disease in man.

WEB downloadable software for training in cardiovascular hemodynamics in the (3-D) stress echo lab

PubMed Central

2010-01-01

When a physiological (exercise) stress echo is scheduled, interest focuses on wall motion segmental contraction abnormalities to diagnose ischemic response to stress, and on left ventricular ejection fraction to assess contractile reserve. Echocardiographic evaluation of volumes (plus standard assessment of heart rate and blood pressure) is ideally suited for the quantitative and accurate calculation of a set of parameters allowing a complete characterization of cardiovascular hemodynamics (including cardiac output and systemic vascular resistance), left ventricular elastance (mirroring left ventricular contractility, theoretically independent of preload and afterload changes heavily affecting the ejection fraction), arterial elastance, ventricular arterial coupling (a central determinant of net cardiovascular performance in normal and pathological conditions), and diastolic function (through the diastolic mean filling rate). All these parameters were previously inaccessible, inaccurate or labor-intensive and now become, at least in principle, available in the stress echocardiography laboratory since all of them need an accurate estimation of left ventricular volumes and stroke volume, easily derived from 3 D echo. Aims of this paper are: 1) to propose a simple method to assess a set of parameters allowing a complete characterization of cardiovascular hemodynamics in the stress echo lab, from basic measurements to calculations 2) to propose a simple, web-based software program, to learn and training calculations as a phantom of the everyday activity in the busy stress echo lab 3) to show examples of software testing in a way that proves its value. The informatics infrastructure is available on the web, linking to http://cctrainer.ifc.cnr.it PMID:21073738

Effect of free fatty acids on myocardial function and metabolism in the ischemic dog heart

PubMed Central

Kjekshus, John K.; Mjøs, Ole D.

1972-01-01

Since elevation of plasma concentrations of free fatty acids (FFA) increases myocardial oxygen consumption without influencing mechanical performance in normal hearts, it was the purpose of this study to determine whether FFA would modify mechanical performance at limited oxygen supply. Left coronary blood flow was reduced by gradual clamping of a shunt from the left carotid artery until moderate ventricular dilatation supervened. Left ventricular systolic pressure (LVSP), its maximal rate of rise (dP/dt) and stroke volume (SV) were unchanged or slightly reduced. The ischemia resulted in a decrease in myocardial oxygen consumption (MVO2) from 9.7±1.1 ml/min to 7.9±0.8 ml/min, and myocardial lactate uptake was reduced or reversed to excretion. Increasing the plasma concentrations of FFA from 359±47 μEq/1 to 3688±520 μEq/1 by intravenous infusion of a triglyceride emulsion and heparin resulted in further ventricular dilatation, accompanied by increased excretion of lactate. The ventricular decompensation and enhancement of anaerobic myocardial metabolism associated with increased uptake of FFA was not related to changes in coronary flow, MVO2, or LVSP. dP/dt and SV were virtually unchanged. Intravenous infusion of glucose/insulin, which lowered plasma concentrations of FFA, reversed ventricular dilatation and lactate excretion. The data support the hypothesis that high concentrations of FFA play a significant role in increasing myocardial oxygen requirement and thereby promote depression of contractility of the hypoxic heart in experimental animals. Images PMID:5032525

Assessment of the ductus arteriosus in fetuses with tetralogy of Fallot and the implication for postnatal management.

PubMed

Tuo, Giulia; Volpe, Paolo; Buffi, Davide; De Robertis, Valentina; Marasini, Maurizio

2014-01-01

To describe the antenatal and neonatal echocardiographic morphology and flow pattern of the ductus arteriosus in patients with tetralogy of Fallot. We included patients with a prenatal diagnosis of tetralogy of Fallot between January 2006 and December 2012. Among the 52 fetuses with tetralogy of Fallot the severity of right ventricular outflow obstruction was considered mild in 32, moderate in 14, and severe in 6. In the mild right ventricular outflow obstruction group (n = 32) all had normal ductal morphology and flow pattern, eight (25%) elected for termination of pregnancy and two died in the neonatal period from extracardiac causes. In the moderate right ventricular outflow obstruction group (n = 14) the fetuses had a small ductus arteriosus with antegrade but abnormal flow velocity, one (7%) elected for termination of pregnancy. Immediately after birth the ductus arteriosus was very small or already closed at echocardiographic examination. Two out of 13 patients (15%) developed severe hypoxic spells and underwent modified Blalock-Taussig shunt during the neonatal period. Six fetuses were considered to have severe right ventricular outflow obstruction with flow reversal in the ductus arteriosus, three (50%) of whom elected for termination of pregnancy. The other three newborns underwent modified Blalock-Taussig shunt. In fetuses with tetralogy of Fallot, ductal diameter can be reduced even up to prenatal closure. Prenatal ductal morphology assessment may be useful for improving management of patients with moderate right ventricular outflow obstruction and small ductus arteriosus who may become cyanotic at birth. © 2013 Wiley Periodicals, Inc.

Right ventricular presystolic peak velocity represents right ventricular function in stable patients.

PubMed

Giovanardi, Paolo; Tincani, Enrico; Stefanelli, Guglielmo; Turrini, Fabrizio; Magnavacchi, Paolo; Sansoni, Stefania; Zennaro, Mauro; Pinelli, Giovanni; Tondi, Stefano

2017-04-01

Right ventricular (RV) function is difficult to be measured but plays a role in morbility and mortality of patients with cardiopulmonary diseases, so many echocardiographic parameters have been developed from M-mode, B-mode and Doppler tissue imaging (DTI) evaluation. Right ventricular presystolic peak velocity (RVPrP) measured with DTI of the tricuspidal annulus and its changes in RV dysfunction have never been assessed in a patient's cohort of stable patients with cardiovascular risk factors. RVPrP velocity could have a role in RV function evaluation; this study addresses such issue. Four hundred thirty-six consecutive patients were submitted to a complete echocardiographic examination with the contemporary evaluation of the following RV function indexes: Tricuspid Annulus Plane Systolic Excurtion (TAPSE), RV Systolic Peak (RVSyP) and RVPrP. Pulmonary artery systolic pressure (PASP), left ventricular and RV diastolic function were also evaluated. According to TAPSE and RVSyP taken alone or in combination, 113 patients had RV dysfunction, while 323 patients had normal RV function. RVPrP was reduced in patient's group with RV dysfunction with respect to patient's group with preserved RV function (16.48±7.3 cm/s vs. 23.98±8.4 cm/s, respectively, P<0.001). RVPrP was related with RVSyP (P<0.001) and with TAPSE (P=0.002). TAPSE and RVSyP revealed a poor concordance to define RV dysfunction. PASP was higher in patient's group with reduced RV function (P=0.033). The study showed RVPrP able to detect stable patients with RV dysfunction.

Reduced Sodium Current in the Lateral Ventricular Wall Induces Inferolateral J-Waves.

PubMed

Meijborg, Veronique M F; Potse, Mark; Conrath, Chantal E; Belterman, Charly N W; De Bakker, Jacques M T; Coronel, Ruben

2016-01-01

J-waves in inferolateral leads are associated with a higher risk for idiopathic ventricular fibrillation. We aimed to test potential mechanisms (depolarization or repolarization dependent) responsible for inferolateral J-waves. We hypothesized that inferolateral J-waves can be caused by regional delayed activation of myocardium that is activated late during normal conditions. Computer simulations were performed to evaluate how J-point elevation is influenced by reducing sodium current conductivity (GNa), increasing transient outward current conductivity (Gto), or cellular uncoupling in three predefined ventricular regions (lateral, anterior, or septal). Two pig hearts were Langendorff-perfused with selective perfusion with a sodium channel blocker of lateral or anterior/septal regions. Volume-conducted pseudo-electrocardiograms (ECG) were recorded to detect the presence of J-waves. Epicardial unipolar electrograms were simultaneously recorded to obtain activation times (AT). Simulation data showed that conduction slowing, caused by reduced sodium current, in lateral, but not in other regions induced inferolateral J-waves. An increase in transient outward potassium current or cellular uncoupling in the lateral zone elicited slight J-point elevations which did not meet J-wave criteria. Additional conduction slowing in the entire heart attenuated J-waves and J-point elevations on the ECG, because of masking by the QRS. Experimental data confirmed that conduction slowing attributed to sodium channel blockade in the left lateral but not in the anterior/septal ventricular region induced inferolateral J-waves. J-waves coincided with the delayed activation. Reduced sodium current in the left lateral ventricular myocardium can cause inferolateral J-waves on the ECG.

Restrictive Cardiomyopathy Associated With Long-Term Use of Hydroxychloroquine for Systemic Lupus Erythematosus.

PubMed

Sabato, Leah A; Mendes, Lisa A; Cox, Zachary L

2017-10-01

Hydroxychloroquine (HQ) is commonly prescribed for autoimmune diseases such as systemic lupus erythematosus. We report a case of a 75-year-old female presenting with de novo decompensated heart failure and restrictive cardiomyopathy (left ventricular ejection fraction: 40%-45%) after treatment with HQ for more than 11 years. Hydroxychloroquine was discontinued, and follow-up echocardiogram 57 days after discontinuation showed normalization of her left ventricular ejection fraction. A score of 7 on the Naranjo Adverse Drug Reaction Probability Scale indicates that HQ is a probable cause of this patient's cardiomyopathy. An adverse drug effect due to HQ should be considered in treated patients who present with restrictive cardiomyopathy. Discontinuation may allow for partial or complete reversal of the cardiomyopathy.

Anomalous left coronary artery from the pulmonary artery with a large patent ductus arteriosus: aversion of a catastrophe.

PubMed

Aggarwal, Sanjeev; Delius, Ralph E; Pettersen, Michael D

2013-01-01

We present an infant who had an anomalous left coronary artery arising from the pulmonary artery (ALCAPA) and a large patent ductus arteriosus (PDA), who was diagnosed before a potentially catastrophic closure of PDA. In the presence of normal left ventricular function and the absence of coronary artery collaterals, it is difficult to diagnose ALCAPA. A disproportionate degree of left ventricular dilation and severity of mitral valve regurgitation relative to the degree of PDA shunt, and echogenic papillary muscles on an echocardiogram should raise a suspicion of coronary artery anomalies. The infant underwent surgical ligation of PDA with translocation of coronary arteries and had an uneventful recovery. © 2012 Wiley Periodicals, Inc.

Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction: The CAMERA-MRI Study.

PubMed

Prabhu, Sandeep; Taylor, Andrew J; Costello, Ben T; Kaye, David M; McLellan, Alex J A; Voskoboinik, Aleksandr; Sugumar, Hariharan; Lockwood, Siobhan M; Stokes, Michael B; Pathik, Bhupesh; Nalliah, Chrishan J; Wong, Geoff R; Azzopardi, Sonia M; Gutman, Sarah J; Lee, Geoffrey; Layland, Jamie; Mariani, Justin A; Ling, Liang-Han; Kalman, Jonathan M; Kistler, Peter M

2017-10-17

Atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) frequently co-exist despite adequate rate control. Existing randomized studies of AF and LVSD of varying etiologies have reported modest benefits with a rhythm control strategy. The goal of this study was to determine whether catheter ablation (CA) for AF could improve LVSD compared with medical rate control (MRC) where the etiology of the LVSD was unexplained, apart from the presence of AF. This multicenter, randomized clinical trial enrolled patients with persistent AF and idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%). After optimization of rate control, patients underwent cardiac magnetic resonance (CMR) to assess LVEF and late gadolinium enhancement, indicative of ventricular fibrosis, before randomization to either CA or ongoing MRC. CA included pulmonary vein isolation and posterior wall isolation. AF burden post-CA was assessed by using an implanted loop recorder, and adequacy of MRC was assessed by using serial Holter monitoring. The primary endpoint was change in LVEF on repeat CMR at 6 months. A total of 301 patients were screened; 68 patients were enrolled between November 2013 and October 2016 and randomized with 33 in each arm (accounting for 2 dropouts). The average AF burden post-CA was 1.6 ± 5.0% at 6 months. In the intention-to-treat analysis, absolute LVEF improved by 18 ± 13% in the CA group compared with 4.4 ± 13% in the MRC group (p < 0.0001) and normalized (LVEF ≥50%) in 58% versus 9% (p = 0.0002). In those undergoing CA, the absence of late gadolinium enhancement predicted greater improvements in absolute LVEF (10.7%; p = 0.0069) and normalization at 6 months (73% vs. 29%; p = 0.0093). AF is an underappreciated reversible cause of LVSD in this population despite adequate rate control. The restoration of sinus rhythm with CA results in significant improvements in ventricular function, particularly in the absence of ventricular fibrosis on CMR. This outcome challenges the current treatment paradigm that rate control is the appropriate strategy in patients with AF and LVSD. (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction [CAMERA-MRI]; ACTRN12613000880741). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Cardiac troponin T is necessary for normal development in the embryonic chick heart.

PubMed

England, Jennifer; Pang, Kar Lai; Parnall, Matthew; Haig, Maria Isabel; Loughna, Siobhan

2016-09-01

The heart is the first functioning organ to develop during embryogenesis. The formation of the heart is a tightly regulated and complex process, and alterations to its development can result in congenital heart defects. Mutations in sarcomeric proteins, such as alpha myosin heavy chain and cardiac alpha actin, have now been associated with congenital heart defects in humans, often with atrial septal defects. However, cardiac troponin T (cTNT encoded by gene TNNT2) has not. Using gene-specific antisense oligonucleotides, we have investigated the role of cTNT in chick cardiogenesis. TNNT2 is expressed throughout heart development and in the postnatal heart. TNNT2-morpholino treatment resulted in abnormal atrial septal growth and a reduction in the number of trabeculae in the developing primitive ventricular chamber. External analysis revealed the development of diverticula from the ventricular myocardial wall which showed no evidence of fibrosis and still retained a myocardial phenotype. Sarcomeric assembly appeared normal in these treated hearts. In humans, congenital ventricular diverticulum is a rare condition, which has not yet been genetically associated. However, abnormal haemodynamics is known to cause structural defects in the heart. Further, structural defects, including atrial septal defects and congenital diverticula, have previously been associated with conduction anomalies. Therefore, to provide mechanistic insights into the effect that cTNT knockdown has on the developing heart, quantitative PCR was performed to determine the expression of the shear stress responsive gene NOS3 and the conduction gene TBX3. Both genes were differentially expressed compared to controls. Therefore, a reduction in cTNT in the developing heart results in abnormal atrial septal formation and aberrant ventricular morphogenesis. We hypothesize that alterations to the haemodynamics, indicated by differential NOS3 expression, causes these abnormalities in growth in cTNT knockdown hearts. In addition, the muscular diverticula reported here suggest a novel role for mutations of structural sarcomeric proteins in the pathogenesis of congenital cardiac diverticula. From these studies, we suggest TNNT2 is a gene worthy of screening for those with a congenital heart defect, particularly atrial septal defects and ventricular diverticula. © 2016 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

Could quantitative longitudinal peak systolic strain help in the detection of left ventricular wall motion abnormalities in our daily echocardiographic practice?

PubMed

Benyounes, Nadia; Lang, Sylvie; Gout, Olivier; Ancédy, Yann; Etienney, Arnaud; Cohen, Ariel

2016-10-01

Transthoracic echocardiography is the most commonly used tool for the detection of left ventricular wall motion (LVWM) abnormalities using "naked eye evaluation". This subjective and operator-dependent technique requires a high level of clinical training and experience. Two-dimensional speckle-tracking echocardiography (2D-STE), which is less operator-dependent, has been proposed for this purpose. However, the role of on-line segmental longitudinal peak systolic strain (LPSS) values in the prediction of LVWM has not been fully evaluated. To test segmental LPSS for predicting LVWM abnormalities in routine echocardiography laboratory practice. LVWM was evaluated by an experienced cardiologist, during routine practice, in 620 patients; segmental LPSS values were then calculated. In this work, reflecting real life, 99.6% of segments were successfully tracked. Mean (95% confidence interval [CI]) segmental LPSS values for normal basal (n=3409), mid (n=3468) and apical (n=3466) segments were -16.7% (-16.9% to -16.5%), -18.2% (-18.3% to -18.0%) and -21.1% (-21.3% to -20.9%), respectively. Mean (95% CI) segmental LPSS values for hypokinetic basal (n=114), mid (n=116) and apical (n=90) segments were -7.7% (-9.0% to -6.3%), -10.1% (-11.1% to -9.0%) and -9.3% (-10.5% to -8.1%), respectively. Mean (95% CI) segmental LPSS values for akinetic basal (n=128), mid (n=95) and apical (n=91) segments were -6.6% (-8.0% to -5.1%), -6.1% (-7.7% to -4.6%) and -4.2% (-5.4% to -3.0%), respectively. LPSS allowed the differentiation between normal and abnormal segments at basal, mid and apical levels. An LPSS value≥-12% detected abnormal segmental motion with a sensitivity of 78% for basal, 70% for mid and 82% for apical segments. Segmental LPSS values may help to differentiate between normal and abnormal left ventricular segments. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Effects of gene knockdown of CNP on ventricular remodeling after myocardial ischemia-reperfusion injury through NPRB/Cgmp signaling pathway in rats.

PubMed

Wu, Lian-He; Zhang, Qi; Zhang, Shen; Meng, Lu-Yu; Wang, Yan-Chi; Sheng, Cun-Jian

2018-02-01

This study aimed to explore effects of CNP on ventricular remodeling following myocardial ischemia-reperfusion (I/R) injury through the NPRB/cGMP signaling pathway. Rat cardiomyocytes were assigned into: control, I/R, I/R + CNP, and I/R + 8-Br-cGMP groups. ELISA, qRT-PCR, and Western blotting were used to detect cGMP content and expression, respectively. After model establishment of I/R rats, normal control, CNP -/- control, I/R, and CNP -/- groups were set. Indexes of heart were detected using echocardiography and hemodynamics. ELISA was used to measure serum CNP, cGMP, LDH, cTn I, CK-MB, TNF-α, and IL-6 levels. Myocardial infarct was identified by TTC staining, and apoptosis conditions by TUNEL staining. QRT-PCR and Western blotting were adopted to detect expressions of CNP, NPRB, cGMP, and apoptosis-related genes. Compared with control group, cGMP contents and expression in the I/R, I/R + CNP and I/R + 8-Br-cGMP groups were decreased. Levels of LVEDV, LVESV, LVDS, LVDD, IVSD, LVM, LVEDP, and LVSP were higher in the I/R, CNP -/- control, and CNP -/- groups than normal control group while LVEF, SV, CO, and ±dp/dtmax were lower. Compared with the normal control group, LDH, cTn I, CK-MB, TNF-α, and IL-6 were higher in the I/R, CNP -/- control and CNP -/- groups; pathological changes and myocardial infarction were observed in the I/R, CNP -/- control, and CNP -/- groups; expressions of apoptosis-related genes in those groups were higher; while CNP, NPRB, cGMP, and Bcl-2 expressions were decreased. We came to the conclusion that gene knockdown of CNP blocks the NPRB/cGMP signaling pathway, thereby aggravating myocardial I/R injury and causing ventricular remodeling in rats. © 2017 Wiley Periodicals, Inc.

Marked regional left ventricular heterogeneity in hypertensive left ventricular hypertrophy patients: a losartan intervention for endpoint reduction in hypertension (LIFE) cardiovascular magnetic resonance and echocardiographic substudy.

PubMed

Biederman, Robert W W; Doyle, Mark; Young, Alistair A; Devereux, Richard B; Kortright, Eduardo; Perry, Gilbert; Bella, Jonathan N; Oparil, Suzanne; Calhoun, David; Pohost, Gerald M; Dell'Italia, Louis J

2008-08-01

Concentric hypertensive left ventricular (LV) hypertrophy is presumed to be a symmetrical process. Using MRI-derived intramyocardial strain, we sought to determine whether segmental deformation was also symmetrical, as suggested by echocardiography. High echocardiographic LV relative wall thickness in hypertensive LV hypertrophy allows preserved endocardial excursion despite depressed LV midwall shortening (MWS). Depressed MWS is an adverse prognostic indicator, but whether this is related to global or regional myocardial depression is unknown. We prospectively compared MWS derived from linear echocardiographic dimensions with MR strain(in) in septal and posterior locations in 27 subjects with ECG LV hypertrophy in the Losartan Intervention for Endpoint Reduction in Hypertension Study. Although MRI-derived mass was higher in patients than in normal control subjects (124.0+/-38.6 versus 60.5+/-13.2g/m(2); P<0.001), fractional shortening (30+/-5% versus 33+/-3%) and end-systolic stress (175+/-22 versus 146+/-28 g/cm(2)) did not differ between groups. However, mean MR(in) was decreased in patients versus normal control subjects (13.9+/-6.8% versus 22.4+/-3.5%), as was echo MWS (13.4+/-2.8% versus 18.2+/-1.4%; both P<0.001). For patients versus normal control subjects, posterior wall(in) was not different (17.8+/-7.1% versus 21.6+/-4.0%), whereas septal(in) was markedly depressed (10.1+/-6.6% versus 23.2+/-3.4%; P<0.001). Although global MWS by echocardiography or MRI is depressed in hypertensive LV hypertrophy, MRI tissue tagging demonstrates substantial regional intramyocardial strain(in) heterogeneity, with most severely depressed strain patterns in the septum. Although posterior wall 2D principal strain was inversely related to radius of curvature, septal strain was not, suggesting that factors other than afterload are responsible for pronounced myocardial strain heterogeneity in concentric hypertrophy.

Idiopathic dilated cardiomyopathy: computerized anatomic study of relashionship between septal and free left ventricle wall

PubMed Central

Juliani, Paulo Sérgio; da Costa, Éder França; Correia, Aristides Tadeu; Monteiro, Rosangela; Jatene, Fabio Biscegli

2014-01-01

Introduction A feature of dilated cardiomyopathy is the deformation of ventricular cavity, which contributes to systolic dysfunction. Few studies have evaluated this deformation bearing in mind ventricular regions and segments of the ventricle, which could reveal important details of the remodeling process, supporting a better understanding of its role in functional impairment and the development of new therapeutic strategies. Objective To evaluate if, in basal, equatorial and apical regions, increased internal transverse perimeter of left ventricle in idiopathic dilated cardiomyopathy occurs proportionally between the septal and non-septal segment. Methods We performed an anatomical study with 28 adult hearts from human cadavers. One group consisted of 18 hearts with idiopathic dilated cardiomyopathy and another group with 10 normal hearts. After lamination and left ventricle digital image capture, in three different regions (base, equator and apex), the transversal internal perimeter of left ventricle was divided into two segments: septal and not septal. These segments were measured by proper software. It was established an index of proportionality between these segments, called septal and non-septal segment index. Then we determined whether this index was the same in both groups. Results Among patients with normal hearts and idiopathic dilated cardiomyopathy, the index of proportionality between the two segments (septal and non-septal) showed no significant difference in the three regions analyzed. The comparison results of the indices NSS/SS among normal and enlarged hearts were respectively: in base 1.99 versus 1.86 (P=0.46), in equator 2.22 versus 2.18 (P=0.79) and in apex 2.96 versus 3.56 (P=0.11). Conclusion In the idiopathic dilated cardiomyopathy, the transversal dilatation of left ventricular internal perimeter occurs proportionally between the segments corresponding to the septum and free wall at the basal, equatorial and apical regions of this chamber. PMID:25372906

T wave alternans threshold late after repair of tetralogy of Fallot

NASA Technical Reports Server (NTRS)

Cheung, Michael M H.; Weintraub, Robert G.; Cohen, Richard J.; Karl, Tom R.; Wilkinson, James L.; Davis, Andrew M.

2002-01-01

INTRODUCTION: Sustained microvolt-level T wave alternans (TWA) is a marker of increased risk for malignant ventricular arrhythmia. There is a significant risk of arrhythmia and sudden death after repair of congenital heart disease. The aim of this study was to determine the prevalence and characteristics of TWA after repair of tetralogy of Fallot (TOF). METHODS AND RESULTS: TWA was evaluated during bicycle exercise in 49 subjects who had consecutively undergone transatrial-transpulmonary repair. Median values for age, age at repair, and follow-up duration were 14.9 years (11.5-20.8), 1.6 years (0.2-4.9), and 11.6 years (9.4-17.2), respectively. All patients were in New York Heart Association functional class I and were asymptomatic. Median QRS duration was 120 msec (80-150). Sustained TWA was detected in 7 (23%) of 31 subjects with adequate tests. In these 7 subjects, median onset heart rate (HR) was 120 (98-155). Median HR threshold as a percentage of predicted maximum HR (220 - age) was 58% (48-77). Sustained TWA prevalence was not significantly different compared with normal subjects (7/31 vs 9/83; P = 0.1). Onset HR in the TOF group was significantly lower [mean (SD) of 122 (20) vs 139 (12), P < 0.05]. In the TOF group with sustained TWA, the TWA occurred in 4 of 7 at <60% predicted maximum HR versus 1 of 9 normal subjects (P < 0.05); 3 of 7 had onset HR <120 versus 0 of 9 normal subjects (P < 0.03). There was no significant difference in age, gender, transannular patch use, restrictive right ventricular physiology, QRS duration, QTc, QT/QRS dispersion, or nonsustained ventricular tachycardia in subjects with or those without sustained TWA. CONCLUSION: The onset HR for sustained TWA is significantly lower after repair of TOF. Further study is required to determine whether this represents an increased risk for arrhythmia in this patient group.

Normal references of right ventricular strain values by two-dimensional strain echocardiography according to the age and gender.

PubMed

Park, Jae-Hyeong; Choi, Jin-Oh; Park, Seung Woo; Cho, Goo-Yeong; Oh, Jin Kyung; Lee, Jae-Hwan; Seong, In-Whan

2018-02-01

Right ventricular (RV) strain values by 2-dimensional strain echocardiography (STE) can be used as objective markers of RV systolic function. However, there is little data about normal reference RV strain values according to age and gender. We measured normal RV strain values by STE. RV strain values were analyzed from the digitally stored echocardiographic images from NORMAL (Normal echOcardiogRaphic diMensions and functions in KoreAn popuLation) study for the measurement of normal echocardiographic values performed in 23 Korean university hospitals. We enrolled total 1003 healthy persons in the NORMAL study. Of them, we analyzed 2-dimensional RV strain values in 493 subjects (261 females, mean 47 ± 15 years old) only with echocardiographic images by GE machines. Their LV systolic and diastolic functions were normal. RV fractional area change was 48 ± 6% and tricuspid annular plane systolic excursion was 23 ± 3 mm. Total RV global longitudinal peak systolic strain (RVGLS total ) was -21.5 ± 3.2%. Females had higher absolute RVGLS total (-22.3 ± 3.3 vs -20.7 ± 2.9%, p < 0.001) than males. Younger (<50 years old) females had higher absolute RVGLS total (-22.9 ± 3.2 vs -20.5 ± 2.8%, p < 0.001) than age matched males. RVGLS total in females gradually increased according to age (p for trend = 0.002) and becomes almost similar in age ≥50 years. However, this trend was not seen in males (p for trend = 0.287), and younger males had similar RVGLS total value to that of older males (age ≥50 years, -20.5 ± 2.8 vs -20.9 ± 3.1%, p = 0.224). We calculated normal RVGLS values in normal population. Females have higher absolute strain values than males, especially in younger age groups (<50 years old).

Drug-eluting stent thrombosis: results from the multicenter Spanish registry ESTROFA (Estudio ESpañol sobre TROmbosis de stents FArmacoactivos).

PubMed

de la Torre-Hernández, José M; Alfonso, Fernando; Hernández, Felipe; Elizaga, Jaime; Sanmartin, Marcelo; Pinar, Eduardo; Lozano, Iñigo; Vazquez, Jose M; Botas, Javier; Perez de Prado, Armando; Hernández, Jose M; Sanchis, Juan; Nodar, Juan M Ruiz; Gomez-Jaume, Alfredo; Larman, Mariano; Diarte, Jose A; Rodríguez-Collado, Javier; Rumoroso, Jose R; Lopez-Minguez, Jose R; Mauri, Josepa

2008-03-11

This study sought to assess the incidence, predictors, and outcome of drug-eluting stent(DES) thrombosis in real-world clinical practice. The DES thromboses in randomized trials could not be comparable to those observed in clinical practice, frequently including off-label indications. We designed a large-scale, nonindustry-linked multicentered registry, with 20 centers in Spain. The participant centers provided follow-up data for their patients treated with DES, reporting a detailed standardized form in the event of any angiography-documented DES-associated thrombosis occurring. Of 23,500 patients treated with DES, definite stent thrombosis(ST) developed in 301: 24 acute, 125 subacute, and 152 late. Of the late, 62 occurred >1 year(very late ST). The cumulative incidence was 2% at 3 years. Antiplatelet treatment had been discontinued in 95 cases(31.6%). No differences in incidences were found among stent types. Independent predictors for subacute ST analyzed in a subgroup of 14,120 cases were diabetes, renal failure, acute coronary syndrome, ST-segment elevation myocardial infarction, stent length, and left anterior descending artery stenting, and for late ST were ST-segment elevation myocardial infarction, stenting in left anterior descending artery, and stent length. Mortality at 1-year follow-up was 16% and ST recurrence 4.6%. Older age, left ventricular ejection fraction <45%, nonrestoration of Thrombolysis In Myocardial Infarction flow grade 3, and additional stenting were independent predictors for mortality. The cumulative incidence of ST after DES implantation was 2% at 3 years. No differences were found among stent types. Patient profiles differed between early and late ST. Short-term prognosis is poor, especially when restoration of normal flow fails.

Prolonged intra-myocardial growth hormone administration ameliorates post-infarction electrophysiologic remodeling in rats.

PubMed

Kontonika, Marianthi; Barka, Eleonora; Roumpi, Maria; La Rocca, Vassilios; Lekkas, Panagiotis; Daskalopoulos, Evangelos P; Vilaeti, Agapi D; Baltogiannis, Giannis G; Vlahos, Antonios P; Agathopoulos, Simeon; Kolettis, Theofilos M

2017-02-01

Experimental studies indicate improved ventricular function after treatment with growth hormone (GH) post-myocardial infarction, but its effect on arrhythmogenesis is unknown. Here, we assessed the medium-term electrophysiologic remodeling after intra-myocardial GH administration in (n = 33) rats. GH was released from an alginate scaffold, injected around the ischemic myocardium after coronary ligation. Two weeks thereafter, ventricular tachyarrhythmias were induced by programmed electrical stimulation. Monophasic action potentials were recorded from the infarct border, coupled with evaluation of electrical conduction and repolarization from a multi-electrode array. The arrhythmia score was lower in GH-treated rats than in alginate-treated rats or controls. The shape and the duration of the action potential at the infarct border were preserved, and repolarization-dispersion was attenuated after GH; moreover, voltage rise was higher and activation delay was shorter. GH normalized also right ventricular parameters. Intra-myocardial GH preserved electrical conduction and repolarization-dispersion at the infarct border and decreased the incidence of induced tachyarrhythmias in rats post-ligation. The long-term antiarrhythmic potential of GH merits further study.

Asymptomatic young man with an incidental murmur.

PubMed

Shojaeifard, Maryam; Pouraliakbar, Hamid Reza; Houshmand, Golnaz

2018-05-31

A 32-year old man was referred to our institution for transthoracic echocardiography (TTE) following detection of an incidental murmur on physical examination before blood donation. He was asymptomatic with no significant medical history. Physical examination revealed dual heart sounds with a grade II/VI systolic murmur heard in the left sternal border. An ECG was in normal sinus rhythm. TTE was performed (figure 1A-C, online supplementary videos 1-4) followed by cardiac CT angiography (CTA) (figure 1D,E).heartjnl;heartjnl-2018-313223v1/F1F1F1Figure 1(A) Transthoracic echocardiography, parasternal left ventricular long axis view. (B) Colour Doppler of modified short axis in the mid-left ventricular level. (C) Doppler flow velocity profile. (D) Cardiac CT angiography (CTA) sagittal reconstruction. (E) Three-dimensional CTA reconstruction of the heart. What is the diagnosis?Pericardial cyst.Ventricular septal defect.Kawasaki.Anomalous left coronary artery from pulmonary artery (ALCAPA). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Variations in the structure of nexuses in the myocardium of the golden hamster Mesocricetus auratus.

PubMed Central

Skepper, J N; Navaratnam, V

1986-01-01

The structure of nexuses in the atrioventricular node of the golden hamster was studied with the transmission electron microscope, using thin sections and freeze-fracture replicas, and was compared with that of nexuses in the working myocardium of the right ventricular wall. Whereas ventricular myocardium contained macular nexuses only, nodal tissue contained annular and linear configurations as well as maculae of varying size. The significance of such variations in nexus pattern is not clear although several hypotheses are discussed in the literature. Measurements made on electron micrographs, after allowing for tilt of the specimen, yielded a particle diameter of 10.59 nm for nodal myocardium and 10.95 nm for ventricular myocardium, both measurements being substantially higher than figures generally cited in the literature. In each area the measurements had a normal distribution suggesting a single type of particle. The small but significant difference in particle size between the two areas is more likely to be caused by dissimilarities in packing arrangement rather than by differences in intrinsic structure or in functional state. Images Fig. 1 Fig. 3 PMID:3693102

Allometric scaling of echocardiographic measurements in healthy Spanish foals with different body weight.

PubMed

Rovira, S; Muñoz, A; Rodilla, V

2009-04-01

Scaling in biology is usually allometric, and therefore, the size of the heart may be expressed as a power function of body weight (BW). The present research analyses the echocardiographic measurements in 68 healthy Spanish foals weighed between 70 and 347kg in order to determine the correct scaling exponent for the allometric equation. The echocardiographic parameters measured were: left ventricular internal dimensions (LVID), free wall thickness (LVFWT), interventricular septum thickness (IVST) at systole (s) and diastole (d), EPSS (distance between the point E of the mitral valve and the interventricular septum), and aorta diameters at the level of the aortic valve (AOD), base of valve leaflets (ABS), sinus of Valsalva (ASV) and sino-tubular junction (AJT). Indices of left ventricular performance were calculated. It was found that LVIDd, IVSTs, AOD, and ASV have a relationship to BW raised to 0.300-0.368 power, whereas left ventricular end-diastolic volume and stroke volume scaled to BW raised to 0.731-0.712 power. With these data, appropriate values can be calculated for normal Spanish foals.

Delayed recovery of left ventricular function after antithyroid treatment. Further evidence for reversible abnormalities of contractility in hyperthyroidism.

PubMed Central

Forfar, J C; Matthews, D M; Toft, A D

1984-01-01

Sequential measurements of systolic time intervals, left ventricular dimensions, and the derived indices of contractility were undertaken at rest and during isometric exercise in 15 hyperthyroid patients before, during, and after antithyroid treatment. At rest hyperthyroidism was characterised by a shortened pre-ejection period and increased velocity of circumferential shortening of the left ventricle. During isometric exercise, however, the pre-ejection period increased significantly beyond that predicted for normal subjects, and the velocity of circumferential fibre shortening fell by 30%. In contrast, both the pre-ejection period and the velocity of circumferential fibre shortening were unchanged during exercise after a stable euthyroid state had been achieved for at least three months. Comparison between exercise responses and thyroid status during antithyroid treatment showed that a biochemical euthyroid state may be achieved many weeks before normalisation of contractile response to exercise. These findings support the hypothesis of reversible depression of left ventricular function in hyperthyroidism. Responses at rest principally reflect the peripheral actions of thyroid hormone excess. PMID:6743439

Adipogenesis and epicardial adipose tissue: A novel fate of the epicardium induced by mesenchymal transformation and PPARγ activation

PubMed Central

Yamaguchi, Yukiko; Cavallero, Susana; Patterson, Michaela; Shen, Hua; Xu, Jian; Kumar, S. Ram; Sucov, Henry M.

2015-01-01

The hearts of many mammalian species are surrounded by an extensive layer of fat called epicardial adipose tissue (EAT). The lineage origins and determinative mechanisms of EAT development are unclear, in part because mice and other experimentally tractable model organisms are thought to not have this tissue. In this study, we show that mouse hearts have EAT, localized to a specific region in the atrial–ventricular groove. Lineage analysis indicates that this adipose tissue originates from the epicardium, a multipotent epithelium that until now is only established to normally generate cardiac fibroblasts and coronary smooth muscle cells. We show that adoption of the adipocyte fate in vivo requires activation of the peroxisome proliferator activated receptor gamma (PPARγ) pathway, and that this fate can be ectopically induced in mouse ventricular epicardium, either in embryonic or adult stages, by expression and activation of PPARγ at times of epicardium–mesenchymal transformation. Human embryonic ventricular epicardial cells natively express PPARγ, which explains the abundant presence of fat seen in human hearts at birth and throughout life. PMID:25646471

Effect of prolonged space flight on cardiac function and dimensions

NASA Technical Reports Server (NTRS)

Henry, W. L.; Epstein, S. E.; Griffith, J. M.; Goldstein, R. E.; Redwood, D. R.

1974-01-01

Echocardiographic studies were performed preflight 5 days before launch and on recovery day and 1, 2, 4, 11, 31 and 68 days postflight. From these echocardiograms measurements were made. From these primary measurements, left ventricular end-diastolic volume, end-systolic volume, stroke volume, and mass were derived using the accepted assumptions. Findings in the Scientist Pilot and Pilot resemble those seen in trained distance runners. Wall thickness measurements were normal in all three crewmembers preflight. Postflight basal studies were unchanged in the Commander on recovery day through 68 days postflight in both the Scientist Pilot and Pilot, however, the left ventricular end-diastolic volume, stroke volume, and mass were decreased slightly. Left ventricular function curves were constructed for the Commander and Pilot by plotting stroke volume versus end-diastolic volume. In both astronauts, preflight and postflight data fell on the same straight line demonstrating that no deterioration in cardiac function had occurred. These data indicate that the cardiovascular system adapts well to prolonged weightlessness and suggest that alterations in cardiac dimensions and function are unlikely to limit man's future in space.

Arrhythmogenic right ventricular cardiomyopathy in Boxer dogs is associated with calstabin2 deficiency

PubMed Central

Oyama, Mark A.; Reiken, Steve; Lehnart, Stephan E.; Chittur, Sridar V.; Meurs, Kathryn M.; Stern, Joshua; Marks, Andrew R.

2010-01-01

Objective To examine the presence and effect of calstabin2-deficiency in Boxer dogs with arrhythmogenic right ventricular cardiomyopathy (ARVC). Animals Thirteen Boxer dogs with ARVC. Materials and methods Tissue samples were collected for histopathology, oligonucleotide microarray, PCR, immunoelectrophoresis, ryanodine channel immunoprecipitation and single-channel recordings, and calstabin2 DNA sequencing. Results In cardiomyopathic Boxer dogs, myocardial calstabin2 mRNA and protein were significantly decreased as compared to healthy control dogs (calstabin2 protein normalized to tetrameric cardiac ryanodine receptor (RyR2) complex: affected, 0.51 ± 0.04; control, 3.81 ± 0.22; P < 0.0001). Calstabin2 deficiency in diseased dog hearts was associated with a significantly increased open probability of single RyR2 channels indicating intracellular Ca2+ leak. PCR-based sequencing of the promoter, exonic and splice site regions of the canine calstabin2 gene did not identify any causative mutations. Conclusions Calstabin2 deficiency is a potential mechanism of Ca2+ leak-induced ventricular arrhythmias and heart disease in Boxer dogs with ARVC. PMID:18515204

A Neonate with Susceptibility to Long QT Syndrome Type 6 who Presented with Ventricular Fibrillation and Sudden Unexpected Infant Death.

PubMed

Sauer, Charles W; Marc-Aurele, Krishelle L

2016-07-28

BACKGROUND This is a case of a neonate with susceptibility to long QT syndrome (LQTS) who presented with a sudden unexpected infant death. Experts continue to debate whether universal electrocardiogram (ECG) screening of all newborns is feasible, practical, and cost-effective. CASE REPORT A 19-day-old neonate was found unresponsive by her mother. ECG showed ventricular fibrillation and a combination of a lidocaine drip plus multiple defibrillations converted the rhythm to normal sinus. Unfortunately, MRI brain imaging showed multiple infarcts and EEG showed burst suppression pattern with frequent seizures; life supportive treatment was stopped and the infant died. Genetic testing revealed two mutations in the KCNE2 gene consistent with susceptibility to LQTS type 6. CONCLUSIONS We believe this case is the first to demonstrate both a precipitating electrocardiographic and genetic cause of death for an infant with LQTS, showing a cause-and-effect relationship between LQTS mutation, ventricular arrhythmia, and death. We wonder whether universal ECG newborn screening to prevent LQTS death could have saved this baby.

[Hypothyroidism in patients with heart disease].

PubMed

Jiskra, Jan

Hypothyroidism is frequently found in patients with heart disease. It is a risk factor for atherosclerosis and ischemic heart disease and has a direct negative effect on both the left and right ventricular functions (hypothyroidism-induced cardiomyopathy). The confirmed manifest hypothyroidism is always a reason for replacement therapy with levothyroxine; regarding patients with heart disease, we always begin treatment with a small dose and increase it gradually. The treatment of subclinical hypothyroidism in patients with heart disease is disputable and its benefits probably depend on age. At a higher age, the therapy-related risks often outweigh its benefits, so we make do with the target levels of the thyroid stimulating hormone being within the upper band of the normal range, or even slightly above it, rather than overdosing the patient. To summarize in a simplified way, the treatment of subclinical hypothyroidism in patients with heart disease is the most effective in younger individuals, mainly those aged below 65, while at a higher age > 80 years the risk usually outweighs the benefit.Key words: cardiovascular risk - hypothyroidism - ischemic heart disease - left ventricular dysfunction - right ventricular dysfunction - subclinical hypothyroidism - thyroid peroxidase antibodies.

Evaluation of concentric left ventricular geometry in humans: evidence for age-related systematic underestimation.

PubMed

de Simone, Giovanni; Daniels, Stephen R; Kimball, Thomas R; Roman, Mary J; Romano, Carmela; Chinali, Marcello; Galderisi, Maurizio; Devereux, Richard B

2005-01-01

There might be limitations in identifying concentric left ventricular (LV) geometry by ratio of diastolic posterior wall thickness (WT(p)) to cavity radius, defined as relative wall thickness (RWT(p)). This study has been designed to evaluate age effects on RWT(p). WT(p), mean of septal thickness and WT(p) (WT(m)), and cavity radius were cross-sectionally evaluated in 766 1- to 85-year-old, normotensive, nonobese subjects and 331 hypertensive Italians (used as a test series). RWT(p) > or =0.43 defined "traditional" concentric LV geometry. The ratios WT(m)/radius (RWT(m)) and RWT(p) increased by 0.005 and 0.006 per year of age in the age stratum up to 17 years and by 0.002 in the older age stratum (18 years or older; all P<0.0001). Thus, RWT(m) and RWT(p) were normalized to average age in both age strata (10 and 46 years) by age-specific regression coefficients. The 90th and 95th percentiles of age-normalized RWT(p) or RWT(m) were 0.40 and 0.42 or 0.41 and 0.43, respectively, in adults and 0.36 and 0.39 or 0.36 and 0.38, respectively in young subjects. In hypertensive subjects, traditional RWT(p) cutoff identified 74 subjects (22%) with concentric LV geometry; by 95th or 90th normal percentiles, normalized RWT(m) identified 112 (34%), or 149 (45%) subjects with concentric LV geometry, and normalized RWT(p) 29% and 39%, respectively (all P<0.0001 versus unadjusted RWT(p)). Thus, prevalence of concentric LV geometry increases with age-normalized RWT. Accordingly, we suggest that concentric LV hypertrophy be defined by coexistence of high LV mass with age-normalized RWT(m) >0.41 or RWT(p) >0.40. Further studies are required to establish prognostic implications of our findings.

Effect of Right Ventricular versus Biventricular Pacing on Electrical Remodeling in the Normal Heart

PubMed Central

Saba, Samir; Mehdi, Haider; Mathier, Michael A.; Islam, M. Zahadul; Salama, Guy; London, Barry

2010-01-01

Background Biventricular (BIV) pacing can improve cardiac function in heart failure by altering the mechanical and electrical substrates. We investigated the effect of BIV versus right ventricular (RV) pacing on the normal heart. Methods and Results Male New Zealand White rabbits (n=33) were divided into 3 groups: sham-operated (control), RV pacing, and BIV pacing groups. Four weeks after surgery, the native QT (p=0.004) interval was significantly shorter in the BIV group compared to the RV or sham-operated groups. Also, compared to rabbits in the RV group, rabbits in the BIV group had shorter RV ventricular effective refractory period (VERP) at all cycle lengths, and shorter LV paced QT interval during the drive train of stimuli and close to refractoriness (p<0.001 for all comparisons). Protein expression of the KVLQT1 was significantly increased in the BIV group compared to the RV and control groups, while protein expression of SCN5A and connexin43 was significantly decreased in the RV compared to the other study groups. Erg protein expression was significantly increased in both pacing groups compared to the controls. Conclusions In this rabbit model, we demonstrate a direct effect of BIV but not RV pacing on shortening the native QT interval as well as the paced QT interval during burst pacing and close to the VERP. These findings underscore the fact that the effect of BIV pacing is partially mediated through direct electrical remodeling and may have implications as to the effect of BIV pacing on arrhythmia incidence and burden. PMID:20042767

Sudden cardiac death: the pro-arrhythmic interaction of an acute loading with an underlying substrate.

PubMed

Sutherland, George R

2017-10-21

Sudden cardiac death (SCD) is a complex phenomenon, occurring either in apparently normal individuals or in those where there is a recognized underlying cardiac abnormality. In both groups, the lethal arrhythmia has frequently been related to the physiologic trigger of either exercise or stress. Prior research into SCD has focused mainly on a combination of identifying either vulnerable myocardial substrates; pharmacological approaches to altering electrical activation/repolarisation in substrates; or the suppression of induced lethal arrhythmias with implantable defibrillators. However, it has been suggested that in a significant number of cases, the interaction of a transient induced trigger with a pre-existing electrical or mechanical substrate is the basis for the induction of the sustained lethal arrhythmia. In this manuscript we will discuss the precise mechanisms whereby one of such potential physiologic trigger: an acute change in systolic blood pressure, can induce a sequence of alterations in global and local cardiac mechanics which in turn result in regional left ventricular post-systolic deformation which, mediated (through stretch-induced changes in local mechano-electrical coupling) provokes local electrical after-depolarisations which can spill over into complex runs of premature ventricular beats. These local acute pressure/stretch induced runs of ventricular ectopy originate in either basal or apical normal myocardium and, in combination with a co-existing distal pro-arrhymic substrate, can interact to induce a lethal arrhythmia. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

A post-transcriptional compensatory pathway in heterozygous ventricular myosin light chain 2-deficient mice results in lack of gene dosage effect during normal cardiac growth or hypertrophy.

PubMed

Minamisawa, S; Gu, Y; Ross, J; Chien, K R; Chen, J

1999-04-09

Our previous study of homozygous mutants of the ventricular specific isoform of myosin light chain 2 (mlc-2v) demonstrated that mlc-2v plays an essential role in murine heart development (Chen, J., Kubalak, S. W., Minamisawa, S., Price, R. L., Becker, K. D., Hickey, R., Ross, J., Jr., and Chien, K. R. (1998) J. Biol. Chem. 273, 1252-1256). As gene dosage of some myofibrillar proteins can affect muscle function, we have analyzed heterozygous mutants in depth. Ventricles of heterozygous mutants displayed a 50% reduction in mlc-2v mRNA, yet expressed normal levels of protein both under basal conditions and following induction of cardiac hypertrophy by aortic constriction. Heterozygous mutants exhibited cardiac function comparable to that of wild-type littermate controls both prior to and following aortic constriction. There were no significant differences in contractility and responses to calcium between wild-type and heterozygous unloaded cardiomyocytes. We conclude that heterozygous mutants show neither a molecular nor a physiological cardiac phenotype either at base line or following hypertrophic stimuli. These results suggest that post-transcriptional compensatory mechanisms play a major role in maintaining the level of MLC-2v protein in murine hearts. In addition, as our mlc-2v knockout mutants were created by a knock-in of Cre recombinase into the endogenous mlc-2v locus, this study demonstrates that heterozygous mlc-2v cre knock-in mice are appropriate for ventricular specific gene targeting.

Abnormal regulation of renin angiotensin aldosterone system is associated with right ventricular dysfunction in hypertension.

PubMed

Gregori, Mario; Tocci, Giuliano; Giammarioli, Benedetta; Befani, Alberto; Ciavarella, Giuseppino Massimo; Ferrucci, Andrea; Paneni, Francesco

2014-02-01

Right ventricular dysfunction (RVD) is a major predictor of cardiovascular mortality. Inadequate suppression of the renin-angiotensin-aldosterone system (RAAS) after postural manoeuvres favours alterations of left ventricular (LV) function. The effects of RAAS dysregulation on RV performance remain elusive. The present study investigated RV function in hypertensive patients with or without altered RAAS activation. Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured in 104 newly diagnosed hypertensive patients after both supine and upright positioning to assess dynamic changes of RAAS induced by antigravitational stress. Twenty-four-hour ambulatory blood pressure monitoring and echocardiographic evaluation of the right ventricle including tissue Doppler imaging (TDI) were performed. Patients were divided as follows: (1) normal PRA and PAC (N group [n = 58]), (2) suppressible RAAS after supine positioning (SR group [n = 24]), and (3), nonsuppressible RAAS (NSR group [n = 22]). RVD was identified by the TDI-derived myocardial performance index (MPI) calculated with a multisegmental approach. Patients in the NSR group had reduced indices of RV function compared with patients in the N and SR groups. MPI of the right ventricle as well as prevalence of RVD were also significantly higher in the NSR group. Regression models showed that inadequate RAAS suppression was independently associated with RVD, regardless of blood pressure values and LV dysfunction (LVD). Patients without supine normalization of RAAS display a significant impairment of RV function. Our findings suggest that a dynamic RAAS evaluation may help to identify hypertensive patients at higher risk of RVD. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Observations on obesity patterns in tetralogy of Fallot patients from childhood to adulthood.

PubMed

Briston, David A; Sabanayagam, Aarthi; Zaidi, Ali N

2017-07-01

Obesity is increasingly prevalent, and abnormal body mass index is a risk factor for cardiovascular disease. There are limited data published regarding body mass index and CHD. We tested the hypothesis that body mass index and obesity prevalence are increasing in patients with tetralogy of Fallot over time by analysing time since surgery, age, height, weight, and body mass index among tetralogy of Fallot patients and demographic data from age-matched controls. NYHA class and left ventricular ejection fraction were analysed in adults. Body mass index was categorised into normal, overweight, and obese in this single-centre, retrospective chart review. Data were collected from 137 tetralogy of Fallot patients (71 men:66 women), of whom 40 had body mass index >25 kg/m2. Tetralogy of Fallot patients aged <6 years had lower body mass index (15.9 versus 17.1; p=0.042) until 16-20 years of age (27.4 versus 25.4; p=0.43). For adult tetralogy of Fallot patients, the mean body mass index was 26.5 but not statistically significantly different from the control cohort. Obese adult patients had significantly higher average NYHA class compared with those of normal weight (p=0.03), but no differences in left ventricular ejection fraction by echocardiography (p=0.55) or cardiac MRI (p=0.26) were noted. Lower body mass index was observed initially in tetralogy of Fallot patients, but by late adolescence no significant difference was observed. As adults, tetralogy of Fallot patients with higher body mass index had increased NYHA class but similar left ventricular ejection fraction.

High Risk of Dementia in Ventricular Enlargement with Normal Pressure Hydrocephalus Related Symptoms1.

PubMed

Koivisto, Anne M; Kurki, Mitja I; Alafuzoff, Irina; Sutela, Anna; Rummukainen, Jaana; Savolainen, Sakari; Vanninen, Ritva; Jääskeläinen, Juha E; Soininen, Hilkka; Leinonen, Ville

2016-03-22

Differential diagnosis of ventricular enlargement with normal pressure hydrocephalus (NPH) related symptoms is challenging. Patients with enlarged ventricles often manifest cognitive deterioration but their long-term outcome is not well known. We aim to evaluate long-term cognitive outcome in patients with enlarged ventricles and clinically suspected NPH. A neurologist and a neurosurgeon clinically evaluated 468 patients with enlarged ventricles and suspected NPH using radiological methods, intraventricular pressure monitoring, and frontal cortical brain biopsy. The neurologist confirmed final diagnoses after a median follow-up interval of 4.8 years. Altogether, 232 patients (50%) with enlarged ventricles did not fulfill the criteria for shunt surgery. The incidence of dementia among patients with enlarged ventricles, and at least one NPH-related symptom with adequate follow-up data (n = 446) was high, varying from 77 (iNPH, shunt responders) to 141/1000 person-years (non-shunted patients with enlarged ventricles). At the end of the follow-up, 59% of all these patients were demented. The demented population comprised 73% of non-shunted patients with enlarged ventricles, 63% of shunted iNPH patients that did not respond to treatment, and 46% of iNPH patients that were initially responsive to shunting. The most common cause of dementia was Alzheimer's disease (n = 94, 36%), followed by vascular dementia (n = 68, 26%). One-half of patients with enlarged ventricles and clinically suspected NPH were not shunted after intraventricular pressure monitoring. Dementia caused by various neurodegenerative diseases was frequently seen in patients with ventricular enlargement. Thus, careful diagnostic evaluation in collaboration with neurologists and neurosurgeons is emphasized.

Unique Cardiac Purkinje Fiber Transient Outward Current β-Subunit Composition

PubMed Central

Xiao, Ling; Koopmann, Tamara T.; Ördög, Balázs; Postema, Pieter G.; Verkerk, Arie O.; Iyer, Vivek; Sampson, Kevin J.; Boink, Gerard J.J.; Mamarbachi, Maya A.; Varro, Andras; Jordaens, Luc; Res, Jan; Kass, Robert S.; Wilde, Arthur A.; Bezzina, C.R.; Nattel, Stanley

2015-01-01

Rationale A chromosomal haplotype producing cardiac overexpression of dipeptidyl peptidase-like protein-6 (DPP6) causes familial idiopathic ventricular fibrillation. The molecular basis of transient outward current (Ito) in Purkinje fibers (PFs) is poorly understood. We hypothesized that DPP6 contributes to PF Ito and that its overexpression might specifically alter PF Ito properties and repolarization. Objective To assess the potential role of DPP6 in PF Ito. Methods and Results Clinical data in 5 idiopathic ventricular fibrillation patients suggested arrhythmia origin in the PF-conducting system. PF and ventricular muscle Ito had similar density, but PF Ito differed from ventricular muscle in having tetraethylammonium sensitivity and slower recovery. DPP6 overexpression significantly increased, whereas DPP6 knockdown reduced, Ito density and tetraethylammonium sensitivity in canine PF but not in ventricular muscle cells. The K+-channel interacting β-subunit K+-channel interacting protein type-2, essential for normal expression of Ito in ventricular muscle, was weakly expressed in human PFs, whereas DPP6 and frequenin (neuronal calcium sensor-1) were enriched. Heterologous expression of Kv4.3 in Chinese hamster ovary cells produced small Ito; Ito amplitude was greatly enhanced by coexpression with K+-channel interacting protein type-2 or DPP6. Coexpression of DPP6 with Kv4.3 and K+-channel interacting protein type-2 failed to alter Ito compared with Kv4.3/K+-channel interacting protein type-2 alone, but DPP6 expression with Kv4.3 and neuronal calcium sensor-1 (to mimic PF Ito composition) greatly enhanced Ito compared with Kv4.3/neuronal calcium sensor-1 and recapitulated characteristic PF kinetic/pharmacological properties. A mathematical model of cardiac PF action potentials showed that Ito enhancement can greatly accelerate PF repolarization. Conclusions These results point to a previously unknown central role of DPP6 in PF Ito, with DPP6 gain of function selectively enhancing PF current, and suggest that a DPP6-mediated PF early-repolarization syndrome might be a novel molecular paradigm for some forms of idiopathic ventricular fibrillation. PMID:23532596

NADPH oxidase contributes to coronary endothelial dysfunction in the failing heart.

PubMed

Zhang, Ping; Hou, Mingxiao; Li, Yunfang; Xu, Xin; Barsoum, Michel; Chen, Yingjie; Bache, Robert J

2009-03-01

Increased reactive oxygen species (ROS) produced by the failing heart can react with nitric oxide (NO), thereby decreasing NO bioavailability. This study tested the hypothesis that increased ROS generation contributes to coronary endothelial dysfunction in the failing heart. Congestive heart failure (CHF) was produced in six dogs by ventricular pacing at 240 beats/min for 4 wk. Studies were performed at rest and during treadmill exercise under control conditions and after treatment with the NADPH oxidase inhibitor and antioxidant apocynin (4 mg/kg iv). Apocynin caused no significant changes in heart rate, aortic pressure, left ventricular (LV) systolic pressure, LV end-diastolic pressure, or maximum rate of LV pressure increase at rest or during exercise in normal or CHF dogs. Apocynin caused no change in coronary blood flow (CBF) in normal dogs but increased CBF at rest and during exercise in animals with CHF (P < 0.05). Intracoronary ACh caused dose-dependent increases of CBF that were blunted in CHF. Apocynin had no effect on the response to ACh in normal dogs but augmented the response to ACh in CHF dogs (P < 0.05). The oxidative stress markers nitrotyrosine and 4-hydroxy-2-nonenal were significantly greater in failing than in normal myocardium. Furthermore, coelenterazine chemiluminescence for O(2)(-) was more than twice normal in failing myocardium, and this difference was abolished by apocynin. Western blot analysis of myocardial lysates demonstrated that the p47(phox) and p22(phox) subunits of NADPH were significantly increased in the failing hearts, while real-time PCR demonstrated that Nox2 mRNA was significantly increased. The data indicate that increased ROS generation in the failing heart is associated with coronary endothelial dysfunction and suggest that NADPH oxidase may contribute to this abnormality.

Feasibility of high-resolution quantitative perfusion analysis in patients with heart failure.

PubMed

Sammut, Eva; Zarinabad, Niloufar; Wesolowski, Roman; Morton, Geraint; Chen, Zhong; Sohal, Manav; Carr-White, Gerry; Razavi, Reza; Chiribiri, Amedeo

2015-02-12

Cardiac magnetic resonance (CMR) is playing an expanding role in the assessment of patients with heart failure (HF). The assessment of myocardial perfusion status in HF can be challenging due to left ventricular (LV) remodelling and wall thinning, coexistent scar and respiratory artefacts. The aim of this study was to assess the feasibility of quantitative CMR myocardial perfusion analysis in patients with HF. A group of 58 patients with heart failure (HF; left ventricular ejection fraction, LVEF ≤ 50%) and 33 patients with normal LVEF (LVEF >50%), referred for suspected coronary artery disease, were studied. All subjects underwent quantitative first-pass stress perfusion imaging using adenosine according to standard acquisition protocols. The feasibility of quantitative perfusion analysis was then assessed using high-resolution, 3 T kt perfusion and voxel-wise Fermi deconvolution. 30/58 (52%) subjects in the HF group had underlying ischaemic aetiology. Perfusion abnormalities were seen amongst patients with ischaemic HF and patients with normal LV function. No regional perfusion defect was observed in the non-ischaemic HF group. Good agreement was found between visual and quantitative analysis across all groups. Absolute stress perfusion rate, myocardial perfusion reserve (MPR) and endocardial-epicardial MPR ratio identified areas with abnormal perfusion in the ischaemic HF group (p = 0.02; p = 0.04; p = 0.02, respectively). In the Normal LV group, MPR and endocardial-epicardial MPR ratio were able to distinguish between normal and abnormal segments (p = 0.04; p = 0.02 respectively). No significant differences of absolute stress perfusion rate or MPR were observed comparing visually normal segments amongst groups. Our results demonstrate the feasibility of high-resolution voxel-wise perfusion assessment in patients with HF.

Disruption of Desmin-Mitochondrial Architecture in Patients with Regurgitant Mitral Valves and Preserved Ventricular Function

PubMed Central

Soorappan, Rajasekaran Namakkal; Ahmad, Shama; Mariappan, Nithya; Litovsky, Silvio; Gupta, Himanshu; Lloyd, Steven G; Denney, Thomas S; Powell, Pamela Cox; Aban, Inmaculada; Collawn, James; Davies, James E; McGiffin, David C; Dell’Italia, Louis J

2016-01-01

Objective Recent studies have demonstrated improved outcomes in patients receiving early surgery for degenerative mitral valvular regurgitation (MR) rather than adhering to conventional guidelines for surgical intervention. However, studies providing a mechanistic basis for these findings are limited. Methods Left ventricular (LV) myocardium from 22 patients undergoing mitral valve repair for Class I indications was evaluated for desmin, the voltage-dependent anion channel, αβ-crystallin, and α, β unsaturated aldehyde 4-hydroxynonelal by fluorescence microscopy and in 6 normal control LV autopsy specimens. Cardiomyocyte ultrastructure was examined by transmission electron microscopy. Magnetic resonance imaging with tissue tagging was performed in 55 normal subjects and 22 MR patients pre- and 6 months post-mitral valve repair. Results LV end-diastolic volume was 1.5-fold (p<0.0001) higher and LV mass to volume ratio was lower in MR (p=0.004) vs. normal and improvement six months after mitral valve surgery. However, LV ejection fraction decreased from 65 ± 7 to 52 ± 9% (p<0.0001) and LV circumferential (p<0.0001) and longitudinal strain decreased significantly below normal values (p=0.002) post-surgery. MR hearts had a 53% decrease in desmin (p<0.0001) and a 2.6-fold increase in desmin aggregates (p<0.0001) vs. normal along with significant, intense perinuclear staining of α, β unsaturated aldehyde 4-hydroxynonelal in areas of mitochondrial breakdown and clustering. Transmission electron microscopy demonstrated numerous electron dense deposits, myofibrillar loss, Z-line abnormalities and extensive granulofilamentous debris identified as desmin positive by immunogold transmission electron microscopy. Conclusion Despite well-preserved preoperative LV ejection fraction, severe oxidative stress and disruption of cardiomyocyte desmin-mitochondrial sarcomeric architecture may explain post-operative LV functional decline and further supports the move toward earlier surgical intervention. PMID:27464577

[Coronary disease with normal coronarography in the black Africans: epidemiological and clinical data in 31 cases. Role of abnormal hemoglobins].

PubMed

Bertrand, E; Renambot, J; Chauvet, J; Seka, R; Ticolat, R; Odi Assamoi, M; Ndori, R; Ekra, A

1993-04-01

The authors studied 31 cases of coronary artery disease with normal or minimally diseases coronary arteries in black Africans, 29.8% of 104 coronary patients undergoing coronary angiography in this series. These 31 cases comprised 16 cases of infarction, 10 cases of angina, 3 ventricular aneurysms and 2 cases of silent ischemia in diabetic patients. Twenty-five patients were men (80.6%). There were 6 women (19.3%) two of whom presented in the post-partum period. The average age of these patients was 45 years (males: 47.7 years; females: 41.8 years). The following risk factors were noted: smoking (60%), hypertension (25.8%), obesity (29%), diabetes (12.9%), serum cholesterol (average 2.15 g/l), serum triglycerides (average 1.25 g/l). The risk index per patient was 1.29. In comparison with coronary patients with angiographic coronary lesions (n = 73), the patients with normal angiography were significantly younger, comprised more females and had fewer risk factors (especially hypertension and diabetes), though this was not statistically significant. The prevalence of inaugural infarction was 81.2% in the cases of infarction with normal coronary arteries. These infarcts may be complicated by ventricular aneurysm formation. Spontaneous spasm was observed in 3 out of 31 patients (9.6%) at coronary angiography. A provocative test was performed in only 2 cases and 1 was positive. This deserves further study and may have therapeutic implications. The authors emphasise the high incidence of hemoglobin S or C traits (57.1%). These heterozygotic hemoglobinopathies could be a risk factor in these coronary patients with normal coronary angiography.

Plasma B-type natriuretic peptide concentration in beta-thalassaemia patients.

PubMed

Aessopos, Athanasios; Farmakis, Dimitrios; Polonifi, Aikaterini; Tsironi, Maria; Fragodimitri, Christina; Hatziliami, Antonia; Karagiorga, Markisia; Diamanti-Kandarakis, Evanthia

2007-05-01

Plasma B-type natriuretic peptide (BNP) concentration has significant diagnostic accuracy and prognostic value in various forms of heart disease. Whether BNP is also useful in the evaluation and management of thalassaemia heart disease remains to be determined. Eighty three thalassaemia major patients; 8 with acutely decompensated heart failure (New York Heart Association [NYHA] class III or IV, group A), 25 with NYHA class II symptoms and impaired systolic left ventricular function (ejection fraction<55% or fractional shortening<30%, group B) and 50 with normal systolic function (group C), as well as 50 healthy controls, were studied. Assessment included history, physical examination, Doppler echocardiography and plasma BNP determination. Mean BNP levels were 431+/-219 pg/mL (range, 283-890 pg/mL) in group A, 158+/-31 pg/mL in group B, 176+/-54 pg/mL in group C and 43+/-24 pg/mL in controls. BNP levels were significantly higher in group A (p<0.001), but did not differ between groups B and C. Moreover, BNP was not correlated with left ventricular end-diastolic diameter, left ventricular mass, right ventricular diameter index, Doppler diastolic indexes (except in group C), the mean 2-year serum ferritin concentration or the peak serum ferritin concentration in any of the three patient groups. A potential deficiency of BNP-related neurohormonal mechanisms may impair its clinical usefulness in thalassaemia major.

First use of an untethered, vented electric left ventricular assist device for long-term support.

PubMed

Frazier, O H

1994-06-01

This report describes the first long-term (505-day) application of the vented electric (VE) HeartMate left ventricular assist device (LVAD) (Thermo Cardiosystems, Inc). The device consists of an abdominally placed, battery-powered titanium blood pump that, in contrast to earlier pneumatically powered systems, allows patients untethered freedom of movement. The batteries last 5 to 8 hours and can be changed on a rotating basis indefinitely. The patient, a 33-year-old man (90 kg, blood type O) with idiopathic cardiomyopathy, experienced end-organ heart failure (New York Heart Association [NYHA] class IV) while he was awaiting heart transplantation. When his hemodynamic criteria met those outlined in the protocol, we implanted the VE-LVAD as a bridge to transplantation. The patient was supported by the device for more than 16 months. His cardiac status returned to NYHA class I, and he was eventually allowed to take day trips outside the hospital as he awaited transplantation. The VE-LVAD enabled the patient to participate in activities such as eating in restaurants, going to movies, and practicing basketball shots. Unfortunately, the patient died suddenly due to a neurological thromboembolic event that occurred on day 503 of VE-LVAD support. The VE-LVAD improved native left ventricular function by chronic unloading, and ventricular remodeling resulted in a more normal configuration anatomically, physiologically, and ultimately, histologically and pathologically.

Transient severe tricuspid regurgitation after transplantation of an extremely oversized donor heart in a child-Does size matter? A case report.

PubMed

Birnbaum, J; Ulrich, S M; Schramm, R; Hagl, C; Lehner, A; Fischer, M; Haas, N A; Heineking, B

2017-02-01

In pediatric heart transplantation, the size of the donor organ is an important criterion for organ allocation. Oversized donor hearts are often accepted with good results, but some complications in relation to a high donor-recipient ratio have been described. Our patient was transplanted for progressive heart failure in dilated cardiomyopathy. The donor-to-recipient weight ratio was 3 (donor weight 65 kg, recipient weight 22 kg). The intra-operative echocardiography before chest closure showed excellent cardiac function, no tricuspid valve regurgitation, and a normal central venous pressure. After chest closure, central venous pressure increased substantially and echocardiography revealed a severe tricuspid insufficiency. As other reasons for right ventricular dysfunction, that is, myocardial ischemia, pulmonary hypertension, and rejection, were excluded, we assumed that the insufficiency was caused by an alteration of the right ventricular geometry. After 1 week, the valve insufficiency regressed to a minimal degree. In pediatric heart transplant patients with a high donor-to-recipient weight ratio, the outlined complication may occur. If other reasons for right ventricular heart failure can be ruled out, this entity is most likely caused by an acute and transient alteration of the right ventricular geometry that may disappear over time. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Hypercholesterolaemia exacerbates ventricular remodelling after myocardial infarction in the rat: role of angiotensin II type 1 receptors

PubMed Central

Mączewski, M; Mączewska, J; Duda, M

2008-01-01

Background and purpose: Diet-induced hypercholesterolaemia exacerbates post-myocardial infarction (MI) ventricular remodelling and heart failure, but the mechanism of this phenomenon remains unknown. This study examined whether worsening of post-MI ventricular remodelling induced by dietary hypercholesterolaemia was related to upregulation of angiotensin II type 1 (AT1) receptor in the rat heart. Experimental approach: MI was induced surgically in rats fed normal or high cholesterol diet. Both groups of rats were then assigned to control, atorvastatin, losartan or atorvastatin+losartan-treated subgroups and followed for 8 weeks. Left ventricular (LV) function was assessed with echocardiography. In isolated hearts, LV pressures were measured with a latex balloon and a tip catheter. AT1-receptor density was assessed in LV membranes with radioligand-binding assays. Key results: High cholesterol diet exacerbated LV dilation and dysfunction in post-MI hearts. Atorvastatin or losartan prevented these hypercholesterolaemia-induced effects, whereas their combination was not more effective than each drug alone. AT1 receptors were upregulated 8 weeks after MI, this was further increased by hypercholesterolaemia and restored to baseline levels by atorvastatin. Conclusions and implications: Hypercholesterolaemia exacerbated LV remodelling and dysfunction in post-MI rat hearts and upregulated cardiac AT1 receptors. All these effects were effectively prevented by atorvastatin. Thus, the pleiotropic statin effects may include interference with the renin-angiotensin system through downregulation of AT1 receptors. PMID:18536757

Two-Dimensional Echocardiography Estimates of Fetal Ventricular Mass throughout Gestation.

PubMed

Aye, Christina Y L; Lewandowski, Adam James; Ohuma, Eric O; Upton, Ross; Packham, Alice; Kenworthy, Yvonne; Roseman, Fenella; Norris, Tess; Molloholli, Malid; Wanyonyi, Sikolia; Papageorghiou, Aris T; Leeson, Paul

2017-08-12

Two-dimensional (2D) ultrasound quality has improved in recent years. Quantification of cardiac dimensions is important to screen and monitor certain fetal conditions. We assessed the feasibility and reproducibility of fetal ventricular measures using 2D echocardiography, reported normal ranges in our cohort, and compared estimates to other modalities. Mass and end-diastolic volume were estimated by manual contouring in the four-chamber view using TomTec Image Arena 4.6 in end diastole. Nomograms were created from smoothed centiles of measures, constructed using fractional polynomials after log transformation. The results were compared to those of previous studies using other modalities. A total of 294 scans from 146 fetuses from 15+0 to 41+6 weeks of gestation were included. Seven percent of scans were unanalysable and intraobserver variability was good (intraclass correlation coefficients for left and right ventricular mass 0.97 [0.87-0.99] and 0.99 [0.95-1.0], respectively). Mass and volume increased exponentially, showing good agreement with 3D mass estimates up to 28 weeks of gestation, after which our measurements were in better agreement with neonatal cardiac magnetic resonance imaging. There was good agreement with 4D volume estimates for the left ventricle. Current state-of-the-art 2D echocardiography platforms provide accurate, feasible, and reproducible fetal ventricular measures across gestation, and in certain circumstances may be the modality of choice. © 2017 S. Karger AG, Basel.

Altered Left Ventricular Ion Channel Transcriptome in a High-Fat-Fed Rat Model of Obesity: Insight into Obesity-Induced Arrhythmogenesis

PubMed Central

Yon, Marianne; Pickavance, Lucy; Yanni Gerges, Joseph; Davis, Gershan; Wilding, John; Jian, Kun; Hart, George; Boyett, Mark

2016-01-01

Introduction. Obesity is increasingly common and is associated with an increased prevalence of cardiac arrhythmias. The aim of this study was to see whether in obesity there is proarrhythmic gene expression of ventricular ion channels and related molecules. Methods and Results. Rats were fed on a high-fat diet and compared to control rats on a normal diet (n = 8). After 8 weeks, rats on the high-fat diet showed significantly greater weight gain and higher adiposity. Left ventricle samples were removed at 8 weeks and mRNA expression of ion channels and other molecules was measured using qPCR. Obese rats had significant upregulation of Cav1.2, HCN4, Kir2.1, RYR2, NCX1, SERCA2a, and RYR2 mRNA and downregulation of ERG mRNA. In the case of HCN4, it was confirmed that there was a significant increase in protein expression. The potential effects of the mRNA changes on the ventricular action potential and intracellular Ca2+ transient were predicted using computer modelling. Modelling predicted prolongation of the ventricular action potential and an increase in the intracellular Ca2+ transient, both of which would be expected to be arrhythmogenic. Conclusion. High-fat diet causing obesity results in arrhythmogenic cardiac gene expression of ion channels and related molecules. PMID:27747100

Left ventricular remodeling in preclinical experimental mitral regurgitation of dogs.

PubMed

Dillon, A Ray; Dell'Italia, Louis J; Tillson, Michael; Killingsworth, Cheryl; Denney, Thomas; Hathcock, John; Botzman, Logan

2012-03-01

Dogs with experimental mitral regurgitation (MR) provide insights into the left ventricular remodeling in preclinical MR. The early preclinical left ventricular (LV) changes after mitral regurgitation represent progressive dysfunctional remodeling, in that no compensatory response returns the functional stroke volume (SV) to normal even as total SV increases. The gradual disease progression leads to mitral annulus stretch and enlargement of the regurgitant orifice, further increasing the regurgitant volume. Remodeling with loss of collagen weave and extracellular matrix (ECM) is accompanied by stretching and hypertrophy of the cross-sectional area and length of the cardiomyocyte. Isolated ventricular cardiomyocytes demonstrate dysfunction based on decreased cell shortening and reduced intracellular calcium transients before chamber enlargement or decreases in contractility in the whole heart can be clinically appreciated. The genetic response to increased end-diastolic pressure is down-regulation of genes associated with support of the collagen and ECM and up-regulation of genes associated with matrix remodeling. Experiments have not demonstrated any beneficial effects on remodeling from treatments that decrease afterload via blocking the renin-angiotensin system (RAS). Beta-1 receptor blockade and chymase inhibition have altered the progression of the LV remodeling and have supported cardiomyocyte function. The geometry of the LV during the remodeling provides insight into the importance of regional differences in responses to wall stress. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of Erythropoietin Administration on Adrenal Glands of Landrace/Large White Pigs after Ventricular Fibrillation.

PubMed

Faa, Armando; Faa, Gavino; Papalois, Apostolos; Obinu, Eleonora; Locci, Giorgia; Pais, Maria Elena; Lelovas, Pavlos; Barouxis, Dimitrios; Pantazopoulos, Charalampos; Vasileiou, Panagiotis V; Iacovidou, Nicoletta; Xanthos, Theodoros

2016-01-01

Aim. To evaluate the effects of erythropoietin administration on the adrenal glands in a swine model of ventricular fibrillation and resuscitation. Methods. Ventricular fibrillation was induced via pacing wire forwarded into the right ventricle in 20 female Landrace/Large White pigs, allocated into 2 groups: experimental group treated with bolus dose of erythropoietin (EPO) and control group which received normal saline. Cardiopulmonary resuscitation (CPR) was performed immediately after drug administration as per the 2010 European Resuscitation Council (ERC) guidelines for Advanced Life Support (ALS) until return of spontaneous circulation (ROSC) or death. Animals who achieved ROSC were monitored, mechanically ventilated, extubated, observed, and euthanized. At necroscopy, adrenal glands samples were formalin-fixed, paraffin-embedded, and routinely processed. Sections were stained with hematoxylin-eosin. Results. Oedema and apoptosis were the most frequent histological changes and were detected in all animals in the adrenal cortex and in the medulla. Mild and focal endothelial lesions were also detected. A marked interindividual variability in the degree of the intensity of apoptosis and oedema at cortical and medullary level was observed within groups. Comparing the two groups, higher levels of pathological changes were detected in the control group. No significant difference between the two groups was observed regarding the endothelial changes. Conclusions. In animals exposed to ventricular fibrillation, EPO treatment has protective effects on the adrenal gland.

Cardiorespiratory interactions in patients with atrial flutter.

PubMed

Masè, Michela; Disertori, Marcello; Ravelli, Flavia

2009-01-01

Respiratory sinus arrhythmia (RSA) is generally known as the autonomically mediated modulation of the sinus node pacemaker frequency in synchrony with respiration. Cardiorespiratory interactions have been largely investigated during sinus rhythm, whereas little is known about interactions during reentrant arrhythmias. In this study, cardiorespiratory interactions at the atrial and ventricular level were investigated during atrial flutter (AFL), a supraventricular arrhythmia based on a reentry, by using cross-spectral analysis and computer modeling. The coherence and phase between respiration and atrial (gamma(AA)(2), phi(AA)) and ventricular (gamma(RR)(2), phi(RR)) interval series were estimated in 20 patients with typical AFL (68.0 +/- 8.8 yr) and some degree of atrioventricular (AV) conduction block. In all patients, atrial intervals displayed oscillations strongly coupled and in phase with respiration (gamma(AA)(2)= 0.97 +/- 0.05, phi(AA) = 0.71 +/- 0.31 rad), corresponding to a paradoxical lengthening of intervals during inspiration. The modulation pattern was frequency independent, with in-phase oscillations and short time delays (0.40 +/- 0.15 s) for respiratory frequencies in the range 0.1-0.4 Hz. Ventricular patterns were affected by AV conduction type. In patients with fixed AV conduction, ventricular intervals displayed oscillations strongly coupled (gamma(RR)(2)= 0.97 +/- 0.03) and in phase with respiration (phi(RR) = 1.08 +/- 0.80 rad). Differently, in patients with variable AV conduction, respiratory oscillations were secondary to Wencheback rhythmicity, resulting in a decreased level of coupling (gamma(RR)(2)= 0.50 +/- 0.21). Simulations with a simplified model of AV conduction showed ventricular patterns to originate from the combination of a respiratory modulated atrial input with the functional properties of the AV node. The paradoxical frequency-independent modulation pattern of atrial interval, the short time delays, and the complexity of ventricular rhythm characterize respiratory arrhythmia during AFL and distinguish it from normal RSA. These peculiar features can be explained by assuming a direct mechanical action of respiration on AFL reentrant circuit.

Year-long upregulation of connexin43 in rabbit hearts by heavy ion irradiation.

PubMed

Amino, Mari; Yoshioka, Koichiro; Fujibayashi, Daisuke; Hashida, Tadashi; Furusawa, Yoshiya; Zareba, Wojciech; Ikari, Yuji; Tanaka, Etsuro; Mori, Hidezo; Inokuchi, Sadaki; Kodama, Itsuo; Tanabe, Teruhisa

2010-03-01

A previous study from our laboratory has shown that a single targeted heavy ion irradiation (THIR; 15 Gy) to rabbit hearts increases connexin43 (Cx43) expression for 2 wk in association with an improvement of conduction, a decrease of the spatial inhomogeneity of repolarization, and a reduction of vulnerability to ventricular arrhythmias after myocardial infarction. This study investigated the time- and dose-dependent effects of THIR (5-15 Gy) on Cx43 expression in normal rabbit hearts (n = 45). Five rabbits without THIR were used as controls. A significant upregulation of Cx43 protein and mRNA in the ventricular myocardium was recognized by immunohistochemistry, Western blotting, and real-time PCR from 2 wk up to 1 yr after a single THIR at 15 Gy. THIR > or =10 Gy caused a significant dose-dependent increase of Cx43 protein and mRNA 2 wk after THIR. Anterior, lateral, and posterior free wall of the left ventricle, interventricular septum, and right ventricular free wall were affected similarly by THIR in terms of Cx43 upregulation. The radiation-induced increase of immunolabeled Cx43 was observed not only at the intercalated disk region but also at the lateral surface of ventricular myocytes. The increase of immunoreactive Cx43 protein was predominant in the membrane fraction insoluble in Triton X-100, that is the Cx43 in the sarcolemma. In vivo examinations of the rabbits 1 yr after THIR (15 Gy) revealed no significant changes in ECGs and echocardiograms (left ventricular dimensions, contractility, and diastolic function), indicating no apparent late radiation injury. A single application of THIR causes upregulation and altered cellular distribution of Cx43 in the ventricles lasting for at least 1 yr. This long-lasting remodeling effect on gap junctions may open the pathway to novel therapy against life threatening ventricular arrhythmias in structural heart disease.

Minimizing right ventricular pacing in pacemaker patients with intact and compromised atrioventricular conduction : Results from the EVITA Trial.

PubMed

Bauer, A; Vermeulen, J; Toivonen, L; Voitk, J; Barr, C; Peytchev, P

2015-12-01

Unnecessary ventricular pacing is associated with increased morbidity and mortality. Over the years different algorithms have been developed to reduce right ventricular pacing. Goal of the present study was to test the efficacy of the ventricular intrinsic preference (VIP) algorithm in patients with atrioventricular intact (AVi) and atrioventricular compromised (AVc) AV-conduction. Evaluation of VIP feature in pacemaker patients (EVITA) was a multicenter, prospective, randomized trial (Trials.gov Identifier: NCT00366158). In total, 389 patients were randomized to AVc group: n = 140/132 VIP OFF/VIP On, AVi group: n = 54/63 VIP OFF/VIP ON). One-month post-implantation AV conduction testing (AVc: PR/AR interval > 210 ms) was performed. Follow-up visits occurred 6 and 12 months after DDD-pacemaker implantation. In AVi and AVc-patients initiation of the VIP feature significantly reduced incidence of ventricular pacing (AVi: 53 ± 38 vs. 9 ± 21%, p = 0.0001; AVc: 79 ± 31 vs. 28 ± 35%, p = 0.0001). DDD-pacemaker implantation per se significantly reduced incidence of AF in VIP ON (AVi 27 vs. 0%, p < 0.0001; AVc 29 vs. 3%, p < 0.0001) and VIP OFF patients (AVi 43 vs. 4%, p < 0.0001; AVc 33 vs. 3, p < 0.0001), without significant differences between VIP ON and OFF groups (p > 0.05). In the AVc group activation of VIP significantly reduced incidence of adverse events (AE). All-cause mortality was not significantly different in VIP ON (n = 5) and VIP OFF (n = 4, p > 0.05) patients. AV search hysteresis (VIP) markedly reduces ventricular pacing both in patients with normal AV conduction and in patients with prolonged PR interval or intermittent AV block.

Effect of phenylephrine bolus administration on left ventricular function during postural hypotension in anesthetized patients.

PubMed

Goertz, A W; Schmidt, M; Lindner, K H; Seefelder, C; Georgieff, M

1993-01-01

To investigate the effect of intravenous (IV) phenylephrine (PHE) bolus administration on left ventricular function in patients who developed postural hypotension during isoflurane anesthesia in the head-up tilt (reverse Trendelenburg) position. Prospective "before-after" trial. Operation theater of a university medical center. 15 ASA physical status I and II patients without cardiovascular disorders. The anesthetized patients were tilted from a supine horizontal to a 30-degree reverse-Trendelenburg position. Once a steady state was achieved, PHE 3 micrograms/kg was administered as an IV bolus dose. Transesophageal echocardiography was used to assess left ventricular function. We measured blood pressure (BP); heart rate; left ventricular end-systolic and end-diastolic area, diameter, and wall thickness; and ejection time at baseline and after tilt, immediately before and for a period of 3 minutes after PHE injection. We calculated fractional area change (FAC), mean velocity of circumferential fiber shortening (mVcf), and end-systolic wall stress. Head-up tilt caused a reduction of mean arterial pressure [from 68 to 54 mmHg (mean)], end-systolic and end-diastolic left ventricular area (from 9.7 to 6.5 cm2 and from 19.2 to 13.1 cm2, respectively) and end-systolic wall stress (from 56 to 33 10(3).dyne/cm2). FAC and mVcf remained unaltered. PHE administration restored baseline values or overcompensated the changes caused by tilt. FAC slightly decreased in response to PHE (from 0.51 to 0.43), end-systolic wall stress increased to 83 10(3).dyne/cm2, and mVcf remained unchanged. PHE bolus administration effectively restored BP and cardiac filling, which were reduced after head-up tilt, without causing a relevant impairment of left ventricular function or an increase in end-systolic wall stress above the upper normal limit.

Intermittent pacemaker dysfunction caused by digital mobile telephones.

PubMed

Naegeli, B; Osswald, S; Deola, M; Burkart, F

1996-05-01

This study was designed to evaluate possible interactions between digital mobile telephones and implanted pacemakers. Electromagnetic fields may interfere with normal pacemaker function. Development of bipolar sensing leads and modern noise filtering techniques have lessened this problem. However, it remains unclear whether these features also protect from high frequency noise arising from digital cellular phones. In 39 patients with an implanted pacemaker (14 dual-chamber [DDD], 8 atrial-synchronized ventricular-inhibited [VDD(R)] and 17 ventricular-inhibited [VVI(R)] pacemakers), four mobile phones with different levels of power output (2 and 8 W) were tested in the standby, dialing and operating mode. During continuous electrocardiographic monitoring, 672 tests were performed in each mode with the phones positioned over the pulse generator, the atrial and the ventricular electrode tip. The tests were carried out at different sensitivity settings and, where possible, in the unipolar and bipolar pacing modes as well. In 7 (18%) of 39 patients, a reproducible interference was induced during 26 (3.9%) of 672 tests with the operating phones in close proximity (<10 cm) to the pacemaker. In 22 dual-chamber (14 DDD, 8 VDD) pacemakers, atrial triggering occurred in 7 (2.8%) of 248 and ventricular inhibition in 5 (2.8%) of 176 tests. In 17 VVI(R) systems, pacemaker inhibition was induced in 14 (5.6%) of 248 tests. Interference was more likely to occur at higher power output of the phone and at maximal sensitivity of the pacemakers (maximal vs. nominal sensitivity, 6% vs. 1.8% positive test results, p = 0.009). When the bipolar and unipolar pacing modes were compared in the same patients, ventricular inhibition was induced only in the unipolar mode (12.5% positive test results, p = 0.0003). Digital mobile phones in close proximity to implanted pacemakers may cause intermittent pacemaker dysfunction with inappropriate ventricular tracking and potentially dangerous pacemaker inhibition.

Pathogenesis of Lethal Cardiac Arrhythmias in Mecp2 Mutant Mice: Implication for Therapy in Rett Syndrome

PubMed Central

McCauley, Mark D.; Wang, Tiannan; Mike, Elise; Herrera, Jose; Beavers, David L.; Huang, Teng-Wei; Ward, Christopher S.; Skinner, Steven; Percy, Alan K.; Glaze, Daniel G.; Wehrens, Xander H. T.; Neul, Jeffrey L.

2013-01-01

Rett Syndrome is a neurodevelopmental disorder typically caused by mutations in Methyl-CpG-Binding Protein 2 (MECP2) in which 26% of deaths are sudden and of unknown cause. To explore the hypothesis that these deaths may be due to cardiac dysfunction, we characterized the electrocardiograms (ECGs) in 379 people with Rett syndrome and found that 18.5% show prolongation of the corrected QT interval (QTc), indicating a repolarization abnormality that can predispose to the development of an unstable fatal cardiac rhythm. Male mice lacking MeCP2 function, Mecp2Null/Y, also have prolonged QTc and show increased susceptibility to induced ventricular tachycardia. Female heterozygous null mice, Mecp2Null/+, show an age-dependent prolongation of QTc associated with ventricular tachycardia and cardiac-related death. Genetic deletion of MeCP2 function in only the nervous system was sufficient to cause long QTc and ventricular tachycardia, implicating neuronally-mediated changes to cardiac electrical conduction as a potential cause of ventricular tachycardia in Rett syndrome. The standard therapy for prolonged QTc in Rett syndrome, β-adrenergic receptor blockers, did not prevent ventricular tachycardia in Mecp2Null/Y mice. To determine whether an alternative therapy would be more appropriate, we characterized cardiomyocytes from Mecp2Null/Y mice and found increased persistent sodium current, which was normalized when cells were treated with the sodium channel-blocking anti-seizure drug phenytoin. Treatment with phenytoin reduced both QTc and sustained ventricular tachycardia in Mecp2Null/Y mice. These results demonstrate that cardiac abnormalities in Rett syndrome are secondary to abnormal nervous system control, which leads to increased persistent sodium current. Our findings suggest that treatment in people with Rett syndrome would be more effective if it targeted the increased persistent sodium current in order to prevent lethal cardiac arrhythmias. PMID:22174313

Ventricular diverticula formation in captive parakeet auklets (Aethia psittacula) secondary to foreign body ingestion.

PubMed

Degernes, Laurel A; Wolf, Karen N; Zombeck, Debbie J; MacLean, Robert A; De Voe, Ryan S

2012-12-01

A captive parakeet auklet at the North Carolina Zoo evaluated for weight loss, lethargy, and dyspnea had radiographic evidence of a distended, stone-filled ventriculus (bird 1). Multiple stones (n = 76) were removed surgically, but the bird died and a large ventricular diverticulum was diagnosed at necropsy. This bird and seven other parakeet auklets had been transferred 3 yr earlier from a zoo in Ohio. Radiographic investigation revealed that 6 of 7 Ohio birds had stones in their ventriculus (n= 2-26), but only 1 of 7 radiographed North Carolina Zoo auklets had one small stone. Further diagnostic imaging (survey and contrast radiographs, fluoroscopy, CT scans [n = 2]) of six Ohio and two North Carolina birds was conducted to determine if other birds had ventricular abnormalities (birds 2-9). No ventricular diverticula were diagnosed using imaging techniques, although two Ohio birds (birds 6 and 7) required surgical intervention to remove 12-26 stones. A small ventricular diverticulum was identified in bird 6 during surgery. That bird died of unrelated causes 11 mo after surgery, but bird 7 remains clinically normal more than 4 yr later, along with four other auklets with stones (n = 2-15; birds 2-5). It is possible that without surgical intervention, these birds may develop ventricular disease, presumably due to chronic mechanical trauma to the thin-walled ventriculus. It was hypothesized that the Ohio birds ingested stones in their previous exhibit, with a loose stone substrate, and retained them for at least 3 yr. Possible causes for stone ingestion include trituration (for grinding, mixing coarse ingesta), gastric parasite reduction, hunger suppression, accidental ingestion while feeding, or behavioral causes, but the underlying cause in these birds was not determined. Based on these results, parakeet auklets and other alcids should not be housed, or at least fed, on a loose stone substrate.

Investigation of a novel algorithm for synchronized left-ventricular pacing and ambulatory optimization of cardiac resynchronization therapy: results of the adaptive CRT trial.

PubMed

Martin, David O; Lemke, Bernd; Birnie, David; Krum, Henry; Lee, Kathy Lai-Fun; Aonuma, Kazutaka; Gasparini, Maurizio; Starling, Randall C; Milasinovic, Goran; Rogers, Tyson; Sambelashvili, Alex; Gorcsan, John; Houmsse, Mahmoud

2012-11-01

In patients with sinus rhythm and normal atrioventricular conduction, pacing only the left ventricle with appropriate atrioventricular delays can result in superior left ventricular and right ventricular function compared with standard biventricular (BiV) pacing. To evaluate a novel adaptive cardiac resynchronization therapy ((aCRT) algorithm for CRT pacing that provides automatic ambulatory selection between synchronized left ventricular or BiV pacing with dynamic optimization of atrioventricular and interventricular delays. Patients (n = 522) indicated for a CRT-defibrillator were randomized to aCRT vs echo-optimized BiV pacing (Echo) in a 2:1 ratio and followed at 1-, 3-, and 6-month postrandomization. The study met all 3 noninferiority primary objectives: (1) the percentage of aCRT patients who improved in their clinical composite score at 6 months was at least as high in the aCRT arm as in the Echo arm (73.6% vs 72.5%, with a noninferiority margin of 12%; P = .0007); (2) aCRT and echo-optimized settings resulted in similar cardiac performance, as demonstrated by a high concordance correlation coefficient between aortic velocity time integrals at aCRT and Echo settings at randomization (concordance correlation coefficient = 0.93; 95% confidence interval 0.91-0.94) and at 6-month postrandomization (concordance correlation coefficient = 0.90; 95% confidence interval 0.87-0.92); and (3) aCRT did not result in inappropriate device settings. There were no significant differences between the arms with respect to heart failure events or ventricular arrhythmia episodes. Secondary end points showed similar benefit, and right-ventricular pacing was reduced by 44% in the aCRT arm. The aCRT algorithm is safe and at least as effective as BiV pacing with comprehensive echocardiographic optimization. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Analysis of transthoracic echocardiographic data in major vascular surgery from a prospective randomised trial comparing sevoflurane and fentanyl with propofol and remifentanil anaesthesia.

PubMed

Lindholm, E E; Aune, E; Frøland, G; Kirkebøen, K A; Otterstad, J E

2014-06-01

The aim of this study was to define pre-operative echocardiographic data and explore if postoperative indices of cardiac function after open abdominal aortic surgery were affected by the anaesthetic regimen. We hypothesised that volatile anaesthesia would improve indices of cardiac function compared with total intravenous anaesthesia. Transthoracic echocardiography was performed pre-operatively in 78 patients randomly assigned to volatile anaesthesia and 76 to total intravenous anaesthesia, and compared with postoperative data. Pre-operatively, 16 patients (10%) had left ventricular ejection fraction < 46%. In 138 patients with normal left ventricular ejection fraction, 5/8 (62%) with left ventricular dilatation and 41/130 (33%) without left ventricular dilatation had evidence of left ventricular diastolic dysfunction (p < 0.001). Compared with pre-operative findings, significant increases in left ventricular end-diastolic volume, left atrial maximal volume, cardiac output, velocity of early mitral flow and early myocardial relaxation occurred postoperatively (all p < 0.001). The ratio of the velocity of early mitral flow to early myocardial relaxation remained unchanged. There were no significant differences in postoperative echocardiographic findings between patients anaesthetised with volatile anaesthesia or total intravenous anaesthesia. Patients had an iatrogenic surplus of approximately 4.1 l of fluid volume by the first postoperative day. N-terminal prohormone of brain natriuretic peptide increased on the first postoperative day (p < 0.001) and remained elevated after 30 days (p < 0.001) in both groups. Although postoperative echocardiographic alterations were most likely to be related to increased preload due to a substantial iatrogenic surplus of fluid, a component of peri-operative myocardial ischaemia cannot be excluded. Our hypothesis that volatile anaesthesia improved indices of cardiac function compared with total intravenous anaesthesia could not be verified. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

Diprosopus with multiple craniofacial, musculoskeletal, and cardiac defects in a purebred Suffolk lamb

PubMed Central

Kerr, Nancy J.

2007-01-01

A stillborn Suffolk ewe lamb with 2 heads was found to have tarsal arthrogryposis, kypholordosis, craniorachischisis totalis, cheiloschisis, palatoschisis, deviation of the right maxilla, prognathia, patent ductus arteriosus, 3 ventricular septal defects, and 4 great vessels. The lamb was born twin to a normal lamb. No definitive etiology was established. PMID:17987971

Anabolic androgenic steroid-induced Takotsubo cardiomyopathy

PubMed Central

Sella, Gianluigi; Bellanti, Giancarlo; Margheri, Massimo

2015-01-01

Anabolic steroid abuse, aimed at increasing muscle mass, has been growing in recent years. We describe a case of a 25-year-old bodybuilder who, after taking nandrolone and stanozolol, presented with Takotsubo syndrome. The angiography showed a normal coronary anatomy with the absence of stenosis. The left ventricular function was completely normalised after 1 week. PMID:25804946

Twenty-four hour Holter monitoring in finishing cattle housed outdoors.

PubMed

Frese, D A; Thomason, J D; Reinhardt, C; Bartle, S; Rethorst, D; Loneragan, G H; Thomson, D

2017-04-01

Atrial premature complexes have been reported to be the most common arrhythmia in cattle and is suspected to be secondary to systemic disease, especially gastrointestinal disease. In order to properly identify pathologic arrhythmia in cattle, the normal rhythm and arrhythmia prevalence should be defined. The objective of this study was to determine the normal heart rate, rhythm, number of ventricular premature complexes (VPCs), and atrial premature complexes (APCs) in unrestrained Angus steers. Twenty-seven client owned steers with unremarkable physical examinations and serum biochemical analyses were used. Twenty-four hour Holter monitors, attached by a custom-made harness, were retrospectively evaluated. Three lead electrocardiographic registrations of good quality and normal sinus rhythm were obtained from all steers in the study. The mean heart rate was 66.8 bpm ± 16.4 bpm. Ventricular premature complexes were rare (noted in 14.8% of steers), and APCs were common (noted in 85% of the steers). Simple second degree AV block was observed in 18.5% of the steers. In summary, healthy steers have rare single VPCs, although it is possible for an individual animal to have apparent more frequent VPCs. Mean heart rate varies with a diurnal pattern similar to other species. Atrial premature complexes are the most prevalent abnormality observed in feedlot steers. Copyright © 2016 Elsevier B.V. All rights reserved.

A proposed role for efflux transporters in the pathogenesis of hydrocephalus

PubMed Central

Krishnamurthy, Satish; Tichenor, Michael D.; Satish, Akhila G.; Lehmann, David B.

2014-01-01

Hydrocephalus is a common brain disorder that is treated only with surgery. The basis for surgical treatment rests on the circulation theory. However, clinical and experimental data to substantiate circulation theory have remained inconclusive. In brain tissue and in the ventricles, we see that osmotic gradients drive water diffusion in water-permeable tissue. As the osmolarity of ventricular CSF increases within the cerebral ventricles, water movement into the ventricles increases and causes hydrocephalus. Macromolecular clearance from the ventricles is a mechanism to establish the normal CSF osmolarity, and therefore ventricular volume. Efflux transporters, (p-glycoprotein), are located along the blood brain barrier and play an important role in the clearance of macromolecules (endobiotics and xenobiotics) from the brain to the blood. There is clinical and experimental data to show that macromolecules are cleared out of the brain in normal and hydrocephalic brains. This article summarizes the existing evidence to support the role of efflux transporters in the pathogenesis of hydrocephalus. The location of p-gp along the pathways of macromolecular clearance and the broad substrate specificity of this abundant transporter to a variety of different macromolecules are reviewed. Involvement of p-gp in the transport of amyloid beta in Alzheimer disease and its relation to normal pressure hydrocephalus is reviewed. Finally, individual variability of p-gp expression might explain the variability in the development of hydrocephalus following intraventricular hemorrhage. PMID:25165050

Relationship between shortening load, contractility, and myocardial energetics in intact dog.

PubMed

Dell'Italia, L J; Evanochko, W T; Blackwell, G G; Pearce, D J; Pohost, G M

1993-06-01

A canine model was developed to estimate left ventricular wall stress, volumes, contractility, and high-energy phosphate metabolites without the need for major surgery. A percutaneously inserted catheter-tip manometer was used to record high-fidelity left ventricular pressure while gradient echo cinemagnetic resonance (cine-MR) imaging alternated with in vivo 31P-nuclear magnetic resonance (NMR) spectroscopy during pharmacological maneuvers to increase cardiac work. Left ventricular circumferential wall stress, volumes, maximum rate of pressure development (dP/dtmax), and the ratio of phosphocreatine (PCr) to gamma-ATP (PCr/gamma-ATP) were recorded sequentially during control 1, dobutamine infusion, control 2, angiotensin infusion, and control 3 in five anesthetized, closed-chest dogs. PCr/gamma-ATP did not change significantly during controls 1-3, angiotensin, and dobutamine infusion. Left ventricular peak positive dP/dt (+dP/dtmax) increased significantly during dobutamine (3,338 +/- 831 mmHg/s, P < 0.001) but was unchanged during angiotensin (1,818 +/- 317 mmHg/s) and controls 1-3 (1,915 +/- 434 vs. 1,808 +/- 478 vs. 1,859 +/- 414 mmHg/s). However, dobutamine decreased the total systolic stress integral (area under the wall stress-time relationship) and end-diastolic and end-systolic volumes, whereas angiotensin increased these parameters compared with control conditions. The unchanged PCr/gamma-ATP is in accord with the results from other open-chest surface coil 31P-NMR experiments in the normal heart. Our assessment of left ventricular functional parameters provides new information that complements these more invasive studies in which heart rate-pressure product was measured during increases in cardiac work.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of the new antiarrhythmic E 047/1 on postoperative ischemia-induced arrhythmias in dogs.

PubMed

Kulier, A H; Novalija, E; Hogan, Q; Vicenzi, M N; Woehlck, H J; Bajic, J; Atlee, J L; Bosnjak, Z J

1999-12-01

Perioperative malignant ventricular tachyarrhythmias pose an imminent clinical danger by potentially precipitating myocardial ischemia and severely compromising hemodynamics. Thus, immediate and effective therapy is required, which is not always provided by currently recommended IV drug regimens, indicating a need for more effective drugs. We examined antiarrhythmic effects of the new benzofurane compound E 047/1 on spontaneous ventricular tachyarrhythmia in a conscious dog model. One day after experimental myocardial infarction, 40 dogs exhibiting tachyarrhythmia randomly received (bolus plus 1-h infusion) E 047/1 6 mg/kg plus 6 mg x kg(-1) x h(-1), lidocaine 1 mg/kg plus 4.8 mg x kg(-1) x h(-1), flecainide 1 mg/kg plus 0.05 mg x kg(-1) x h(-1), amiodarone 10 mg/kg plus 1.8 mg x kg(-1) x h(-1), or bretylium 10 mg/kg plus 20 mg x kg(-1) x h(-1). Electrocardiogram was evaluated for number of premature ventricular contractions (PVC), normally conducted beats originating from the sinoatrial node, and episodes of ventricular tachycardia. Immediately after the bolus, E 047/1 reduced PVCs by 46% and increased sinoatrial beats from 4 to 61 bpm. The ratio of PVCs to total beats decreased from 98% to 58%. Amiodarone and flecainide exhibited antiarrhythmic effects with delayed onset. Lidocaine did not suppress PVCs significantly, and bretylium was proarrhythmic. The antiarrhythmic E 047/1 has desirable features, suppressing ischemia-induced ventricular tachyarrhythmia quickly and efficiently, and may be a useful addition to current therapeutic regimens. Life-threatening arrhythmias of the heart after myocardial infarction or ischemia may be treated quickly and efficiently by the new drug E 047/1.

Cerebrospinal Fluid Clearance in Alzheimer Disease Measured with Dynamic PET.

PubMed

de Leon, Mony J; Li, Yi; Okamura, Nobuyuki; Tsui, Wai H; Saint-Louis, Les A; Glodzik, Lidia; Osorio, Ricardo S; Fortea, Juan; Butler, Tracy; Pirraglia, Elizabeth; Fossati, Silvia; Kim, Hee-Jin; Carare, Roxana O; Nedergaard, Maiken; Benveniste, Helene; Rusinek, Henry

2017-09-01

Evidence supporting the hypothesis that reduced cerebrospinal fluid (CSF) clearance is involved in the pathophysiology of Alzheimer disease (AD) comes primarily from rodent models. However, unlike rodents, in which predominant extracranial CSF egress is via olfactory nerves traversing the cribriform plate, human CSF clearance pathways are not well characterized. Dynamic PET with 18 F-THK5117, a tracer for tau pathology, was used to estimate the ventricular CSF time-activity as a biomarker for CSF clearance. We tested 3 hypotheses: extracranial CSF is detected at the superior turbinates; CSF clearance is reduced in AD; and CSF clearance is inversely associated with amyloid deposition. Methods: Fifteen subjects, 8 with AD and 7 normal control volunteers, were examined with 18 F-THK5117. Ten subjects additionally underwent 11 C-Pittsburgh compound B ( 11 C-PiB) PET scanning, and 8 were 11 C-PiB-positive. Ventricular time-activity curves of 18 F-THK5117 were used to identify highly correlated time-activity curves from extracranial voxels. Results: For all subjects, the greatest density of CSF-positive extracranial voxels was in the nasal turbinates. Tracer concentration analyses validated the superior nasal turbinate CSF signal intensity. AD patients showed ventricular tracer clearance reduced by 23% and 66% fewer superior turbinate CSF egress sites. Ventricular CSF clearance was inversely associated with amyloid deposition. Conclusion: The human nasal turbinate is part of the CSF clearance system. Lateral ventricle and superior nasal turbinate CSF clearance abnormalities are found in AD. Ventricular CSF clearance reductions are associated with increased brain amyloid depositions. These data suggest that PET-measured CSF clearance is a biomarker of potential interest in AD and other neurodegenerative diseases. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Do we overestimate left ventricular ejection fraction by two-dimensional echocardiography in patients with left bundle branch block?

PubMed

Cabuk, Ali K; Cabuk, Gizem; Sayin, Ahmet; Karamanlioglu, Murat; Kilicaslan, Barış; Ekmekci, Cenk; Solmaz, Hatice; Aslanturk, Omer F; Ozdogan, Oner

2018-02-01

Left bundle branch block (LBBB) causes a dyssynchronized contraction of left ventricle. This is a kind of regional wall-motion abnormality and measuring left ventricular ejection fraction (LVEF) by two-dimensional (2D) echocardiography could be less reliable in this particular condition. Our aim was to evaluate the role of dyssynchrony index (SDI), measured by three-dimensional (3D) echocardiography, in assessment of LVEF and left ventricular volumes accurately in patients with LBBB. In this case-control study, we included 52 of 64 enrolled participants (twelve participants with poor image quality were excluded) with LBBB and normal LVEF or nonischemic cardiomyopathy. Left ventricular ejection fraction (LVEF) and left ventricular volumes were assessed by 2D (modified Simpson's rule) and 3D (four beats full volume analysis) echocardiography and the impact of SDI on results were evaluated. In patients with SDI ≥6%, LVEF measurements were significantly different (46.00% [29.50-52.50] vs 37.60% [24.70-45.15], P < .001) between 2D and 3D echocardiography, respectively. In patients with SDI < 6%, there were no significant differences between two modalities in terms of LVEF measurements (54.50% [49.00-59.00] vs 54.25% [40.00-58.25], P = .193). LV diastolic volumes were not significantly different while systolic volumes were underestimated by 2D echocardiography, and this finding was more pronounced when SDI ≥ 6%. In patients with LBBB and high SDI (≥6%), LVEF values were overestimated and systolic volumes were underestimated by 2D echocardiography compared to 3D echocardiography. © 2017 Wiley Periodicals, Inc.

Contractility and Ventricular Systolic Stiffening in Hypertensive Heart Disease: Insights into the Pathogenesis of Heart Failure with Preserved Ejection Fraction

PubMed Central

Borlaug, Barry A.; Lam, Carolyn S.P.; Roger, Véronique L.; Rodeheffer, Richard J.; Redfield, Margaret M.

2009-01-01

Objectives: 1) Compare left ventricular (LV) systolic stiffness and contractility in normal subjects, hypertensives without heart failure, and patients with heart failure and preserved ejection fraction (HFpEF); and 2) Determine whether LV systolic stiffness or myocardial contractility are associated with mortality in HFpEF. Background: Arterial load is increased in hypertension and is matched by increased end-systolic LV stiffness (ventricular-arterial coupling). Increased end-systolic LV stiffness may be mediated by enhanced myocardial contractility or processes which increase passive myocardial stiffness. Methods: Healthy controls (n=617), hypertensives (No HF, n=719) and patients with HFpEF (n=244, 96% hypertensive) underwent echo-Doppler characterization of arterial (Ea) and LV end-systolic (Ees) stiffness (elastance), ventricular-arterial coupling (Ea/Ees ratio), chamber-level and myocardial contractility (stress-corrected midwall shortening). Results: Ea and Ees were similarly elevated in hypertensives with or without HFpEF compared with controls, but ventricular-arterial coupling was similar across groups. In hypertensives, elevated Ees was associated with enhanced chamber-level and myocardial contractility, while in HFpEF, chamber and myocardial contractility were depressed compared with both hypertensives and controls. Group differences persisted after adjusting for geometry. In HFpEF, impaired myocardial contractility (but not Ees) was associated with increased age-adjusted mortality. Conclusions: While arterial load is elevated and matched by increased LV systolic stiffness in hypertension with or without HFpEF, the mechanisms of systolic LV stiffening differ substantially. These data suggest that myocardial contractility increases to match arterial load in asymptomatic hypertensive heart disease, but that progression to HFpEF may be mediated by processes which simultaneously impair myocardial contractility and increase passive myocardial stiffness. PMID:19628115

Two-dimensional speckle tracking echocardiography demonstrates no effect of active acromegaly on left ventricular strain.

PubMed

Volschan, I C M; Kasuki, L; Silva, C M S; Alcantara, M L; Saraiva, R M; Xavier, S S; Gadelha, M R

2017-06-01

Speckle tracking echocardiography (STE) allows for the study of myocardial strain (ε), a marker of early and subclinical ventricular systolic dysfunction. Cardiac disease may be present in patients with acromegaly; however, STE has never been used to evaluate these patients. To evaluate left ventricular (LV) global longitudinal strain in patients with active acromegaly with normal LV systolic function. Cross-sectional clinical study. Patients with active acromegaly with no detectable heart disease and a control group were matched for age, gender, arterial hypertension and diabetes mellitus underwent STE. Global LV longitudinal ε (GLS), left ventricular mass index (LVMi), left ventricular ejection fraction (LVEF) and relative wall thickness (RWT) were obtained via two-dimensional (2D) echocardiography using STE. Thirty-seven patients with active acromegaly (mean age 45.6 ± 13.8; 48.6% were males) and 48 controls were included. The mean GLS was not significantly different between the acromegaly group and the control group (in %, -20.1 ± 3.1 vs. -19.4 ± 2.2, p = 0.256). Mean LVMi was increased in the acromegaly group (in g/m 2 , 101.6 ± 27.1 vs. 73.2 ± 18.6, p < 0.01). There was a negative correlation between LVMi and GLS (r = -0.39, p = 0.01). Acromegaly patients, despite presenting with a higher LVMi when analyzed by 2D echocardiography, did not present with impairment in the strain when compared to a control group; this finding indicates a low chance of evolution to systolic dysfunction and agrees with recent studies that show a lower frequency of cardiac disease in these patients.

Circulating microRNAs in arrhythmogenic right ventricular cardiomyopathy with ventricular arrhythmia.

PubMed

Yamada, Shinya; Hsiao, Ya-Wen; Chang, Shih-Lin; Lin, Yenn-Jiang; Lo, Li-Wei; Chung, Fa-Po; Chiang, Shuo-Ju; Hu, Yu-Feng; Tuan, Ta-Chuan; Chao, Tze-Fan; Liao, Jo-Nan; Lin, Chin-Yu; Chang, Yao-Ting; Te, Abigail Louise D; Tsai, Yung-Nan; Chen, Shih-Ann

2018-06-01

MicroRNAs (miRNAs) have been implicated in cardiac diseases. This study aimed to characterize the circulating miRNAs in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and correlate the miRNAs with the clinical outcomes of ARVC. This study included 62 patients with ventricular arrhythmia (VA): 28 patients (45%) had definite ARVC, 11 (18%) had borderline or possible ARVC, and 23 (37%) had idiopathic ventricular tachycardia (VT). In addition, 33 age- and sex-matched healthy subjects were enrolled as normal control subjects. The expression of selected miRNAs was analysed in all study subjects. The clinical outcomes of patients with definite ARVC after catheter ablation were further investigated. On the basis of the miRNA polymerase chain reaction array, we selected 11 miRNAs for analysis of their expression in the plasma of all subjects. Definite ARVC patients had significantly higher expression of circulating miR-144-3p, 145-5p, 185-5p, and 494 than the three other groups. Out of 25 definite ARVC patients who underwent radiofrequency catheter ablation, recurrent VA occurred in 8 patients (32%) during the follow-up period (45 ± 20 months). Definite ARVC patients with recurrent VA had a higher level of circulating miR-494 than did those without recurrence. Receiver operating characteristic analysis showed miR-494 to be a predictive factor of recurrent VA (area under the curve: 0.832). Plasma levels of miR-144-3p, 145-5p, 185-5p, and 494 were significantly elevated in definite ARVC patients with VA. An increased plasma level of miR-494 was associated with the recurrence of VA after ablation in definite ARVC patients.

Effect of mental challenge induced by movie clips on action potential duration in normal human subjects independent of heart rate.

PubMed

Child, Nicholas; Hanson, Ben; Bishop, Martin; Rinaldi, Christopher A; Bostock, Julian; Western, David; Cooklin, Michael; O'Neil, Mark; Wright, Matthew; Razavi, Reza; Gill, Jaswinder; Taggart, Peter

2014-06-01

Mental stress and emotion have long been associated with ventricular arrhythmias and sudden death in animal models and humans. The effect of mental challenge on ventricular action potential duration (APD) in conscious healthy humans has not been reported. Activation recovery intervals measured from unipolar electrograms as a surrogate for APD (n=19) were recorded from right and left ventricular endocardium during steady-state pacing, whilst subjects watched an emotionally charged film clip. To assess the possible modulating role of altered respiration on APD, the subjects then repeated the same breathing pattern they had during the stress, but without the movie clip. Hemodynamic parameters (mean, systolic, and diastolic blood pressure, and rate of pressure increase) and respiration rate increased during the stressful part of the film clip (P=0.001). APD decreased during the stressful parts of the film clip, for example, for global right ventricular activation recovery interval at end of film clip 193.8 ms (SD, 14) versus 198.0 ms (SD, 13) during the matched breathing control (end film left ventricle 199.8 ms [SD, 16] versus control 201.6 ms [SD, 15]; P=0.004). Respiration rate increased during the stressful part of the film clip (by 2 breaths per minute) and was well matched in the respective control period without any hemodynamic or activation recovery interval changes. Our results document for the first time direct recordings of the effect of a mental challenge protocol on ventricular APD in conscious humans. The effect of mental challenge on APD was not secondary to emotionally induced altered respiration or heart rate. © 2014 American Heart Association, Inc.

In vivo epicardial force and strain characterisation in normal and MLP-knockout murine hearts.

PubMed

Michaelides, M; Georgiadou, S; Constantinides, C

2015-07-01

The study's objective is to quantify in vivo epicardial force and strain in the normal and transgenic myocardium using microsensors.Male mice (n = 39), including C57BL/6 (n = 26), 129/Sv (n = 5), wild-type (WT) C57  ×  129Sv (n = 5), and muscle LIM protein (MLP) knock-out (n = 3), were studied under 1.5% isoflurane anaesthesia. Microsurgery allowed the placement of two piezoelectric crystals at longitudinal epicardial loci at the basal, middle, and apical LV regions, and the independent (and/or concurrent) placement of a cantilever force sensor. The findings demonstrate longitudinal contractile and relaxation strains that ranged between 4.8-9.3% in the basal, middle, and apical regions of C57BL/6 mice, and in the mid-ventricular regions of 129/Sv, WT, and MLP mice. Measured forces ranged between 3.1-8.9 mN. The technique's feasibility is also demonstrated in normal mice following afterload, occlusion-reperfusion challenges.Furthermore, the total mid-ventricular forces developed in MLP mice were significantly reduced compared to the WT controls (5.9  ±  0.4 versus 8.9  ±  0.2 mN, p < 0.0001), possibly owing to the fibrotic and stiffer myocardium. No significant strain differences were noted between WT and MLP mice.The possibility of quantifying in vivo force and strain from the normal murine heart is demonstrated with a potential usefulness in the characterisation of transgenic and diseased mice, where regional myocardial function may be significantly altered.

Echocardiography of the normal camel (Camelus dromedaries) heart: technique and cardiac dimensions

PubMed Central

2012-01-01

Background Echocardiography and intra-cardiac dimensions have not previously been reported in adult camels despite its potential application for medical purpose. The aim of this study was to describe the results of a prospective study, aiming to report normal cardiac appearance and normal chamber dimensions in adult camels (Camelus dromedarius). Results On the right side, when the probe was placed in the 5th or 4th intercostal space (ICS), the caudal long-axis four-chamber view of the ventricles, atria, and the interventricular septum was obtained. Placing the probe slightly more cranially in the 4th ICS, the caudal long-axis four-chamber view and the caudal long-axis view of the left ventricular outflow tract (LVOT) were imaged. In 7 camels, a hybrid view between a “four-chamber” and “LVOT view” was imaged from the same position. The short-axis view of the ventricles was obtained in the 4th ICS where the transducer was rotated between 0° and 25°. Placement of the transducer in the 3rd ICS allowed visualisation of the right ventricular outflow tract (RVOT). On the left side, when the probe was placed in the 5th or 4th ICS, a four-chamber view was obtained. The LVOT is imaged in the 4th ICS and the RVOT was seen from the 3rd ICS. Conclusions This study showed that it is possible to obtain good-quality echocardiograms in adult camels and provide normal cardiac dimensions. This study could be used as a reference for further studies concerning camels with cardiac diseases. PMID:22862855

Organotypic distribution of stem cell markers in formalin-fixed brain harboring glioblastoma multiforme.

PubMed

Schrot, Rudolph J; Ma, Joyce H; Greco, Claudia M; Arias, Angelo D; Angelastro, James M

2007-11-01

The role of stem cells in the origin, growth patterns, and infiltration of glioblastoma multiforme is a subject of intense investigation. One possibility is that glioblastoma may arise from transformed stem cells in the ventricular zone. To explore this hypothesis, we examined the distribution of two stem cell markers, activating transcription factor 5 (ATF5) and CD133, in an autopsy brain specimen from an individual with glioblastoma multiforme. A 41-year-old male with a right posterior temporal glioblastoma had undergone surgery, radiation, and chemotherapy. The brain was harvested within several hours after death. After formalin fixation, sectioning, and mapping of tumor location in the gross specimen, histologic specimens were prepared from tumor-bearing and grossly normal hemispheres. Fluorescence immunohistochemistry and colorimetric staining were performed for ATF5 and CD133. Both markers co-localized to the ependymal and subependymal zones on the side of the tumor, but not in the normal hemisphere or more rostrally in the affected hemisphere. ATF5 staining was especially robust within the diseased hemisphere in histologically normal ependyma. To our knowledge, this is the first in situ demonstration of stem cell markers in whole human brain. These preliminary results support the hypothesis that some glioblastomas may arise from the neurogenic zone of the lateral ventricle. The robust staining for ATF5 and CD133 in histologically normal ventricular zone suggests that an increase in periventricular stem cell activity occurred in this patient on the side of the tumor, either as a localized response to brain injury or as an integral component of oncogenesis and tumor recurrence.

Ventricular Tachycardia or not? An Unexpected Reason of Wide QRS Complex Tachycardia in a Young Healthy Man: Sodium Bicarbonate.

PubMed

Eyuboglu, Mehmet

2016-10-01

Ventricular tachycardia (VT) is life-threatening subgroup of wide QRS complex tachycardia (WCT). VT is usually associated with structural heart diseases, but it can occur in the absence of any cardiovascular diseases. Adverse cardiac effect of sodium bicarbonate in healthy subjects is not well described. A 30-year-old healthy man with excessive intake of sodium bicarbonate-related VT is presented. He was using sodium bicarbonate during last 2 months to lose weight. He has no risk factors and any cardiovascular or systemic diseases. After intravenous administration of amiodarone, tachycardia ended and his rhythm converted to sinus rhythm with normal electrocardiogram. Patient is asymptomatic, and no VT was observed without any medications at 1 year of follow-up.

Idiopathic annular dilation: a rare cause of isolated severe tricuspid regurgitation.

PubMed

Girard, S E; Nishimura, R A; Warnes, C A; Dearani, J A; Puga, F J

2000-03-01

The management of patients with severe tricuspid regurgitation (TR) requires the clinician to clarify the mechanism of regurgitation. Primary disorders of the tricuspid valve, either congenital or acquired, may be readily identified by echocardiography. Severe TR most often results from left-sided heart disease and secondary pulmonary hypertension. Cardiomyopathic processes may also cause right ventricular failure and functional TR. We report three patients with severe TR due to idiopathic annular dilation. The tricuspid valves were otherwise normal on surgical inspection, and the pulmonary pressures were not significantly elevated. Each patient was aged over 65 years and had chronic atrial fibrillation with preserved left ventricular systolic function. Surgical treatment was associated with marked clinical improvement. Clinicians should recognize this unusual but treatable cause of right-sided congestive heart failure.

Neonatal Meningoventriculitis Due to Proteus Mirabilis – A Case Report

PubMed Central

Juyal, Deepak; Rathaur, Vyas Kumar; Sharma, Neelam

2013-01-01

A five day old full term born baby was admitted to our Neonatal Intensive Care Unit with seizures, opisthotonous posture and was icteric upto thigh. Baby had a three day history of poor feeding, lethargy and abnormal body movements. Mother was a 29 years old primigravida and had a normal vaginal delivery at home. Sepsis profile of the patient was requested, lumbar puncture and ventricular tap was performed. Patient was put on third generation cephalosporins, aminoglycosides and phenobarbitone. Culture and sensitivity report of blood, Cerebro spinal fluid and ventricular fluid showed Proteus mirabilis. Computerized Tomography scan showed a large parenchymal lesion in the right frontal lobe and diffuse ependymal enhancement along both the lateral ventricles suggestive of meningoventriculitis. We hereby present a fatal case of neonatal meningoventriculitis due to Proteus mirabilis. PMID:23543669

Outcome of infants shunted for post-haemorrhagic ventricular dilatation.

PubMed

Hislop, J E; Dubowitz, L M; Kaiser, A M; Singh, M P; Whitelaw, A G

1988-08-01

Between April 1980 and March 1986, 19 infants underwent cerebrospinal fluid (CSF) shunting procedures for post-haemorrhagic ventricular dilatation at the Hammersmith Hospital, London. A total of 58 shunt-related procedures have been performed on these children. The major perioperative complication was seizure activity (eight children). Postoperative complications included infection (12 shunts) and blockage (29 shunts). Prophylactic antibiotics failed to prevent shunt infection. The likelihood of the first shunt failing was significantly reduced by greater weight of the infant and lower CSF protein at surgery. Long-term outcome was poor: three have died and another four are quadriplegic with severe mental retardation. Only four children are developmentally normal. These outcomes cannot be related to the shunt surgery or its complications, but correlate best with pre-operative parenchymal brain-lesions, as shown on ultrasound scans.

Cardiovascular adaptations to marathon running : the marathoner's heart.

PubMed

Thompson, Paul D

2007-01-01

Endurance exercise training produces a series of cardiac adaptations including resting bradycardia, first and second degree atrioventricular block, increased intolerance to orthostatic stress, and enlargement of the left ventricular walls and of all cardiac chambers. Cardiac dimensions may be increased beyond the upper limits of normal and some endurance athletes demonstrate mild reductions in estimated left ventricular ejection fraction. Among athletes, such adaptations occur primarily in well trained endurance athletes. Clinicians should be aware of the cardiac changes accompanying endurance training to avoid unnecessary evaluation of physiological changes. On the other hand, the presence of conduction abnormalities or cardiac enlargement in low level or recreational athletes should prompt a search for pathological causes. Many of these findings were presented in the 1977 report on the marathon and have simply been better defined with subsequent studies.

Evidence of an application of a variable MEMS capacitive sensor for detecting shunt occlusions

NASA Astrophysics Data System (ADS)

Apigo, David J.; Bartholomew, Philip L.; Russell, Thomas; Kanwal, Alokik; Farrow, Reginald C.; Thomas, Gordon A.

2017-04-01

A sensor was tested subdural and in vitro, simulating a supine infant with a ventricular-peritoneal shunt and controlled occlusions. The variable MEMS capacitive device is able to detect and forecast blockages, similar to early detection procedures in cancer patients. For example, with gradual occlusion development over a year, the method forecasts a danger over one month ahead of blockage. The method also distinguishes between ventricular and peritoneal occlusions. Because the sensor provides quantitative data on the dynamics of the cerebrospinal fluid, it can help test new therapies and work toward understanding hydrocephalus as well as idiopathic normal pressure hydrocephalus. The sensor appears to be a substantial advance in treating brain injuries treated with shunts and has the potential to bring significant impact in a clinical setting.

Exercise-induced pulmonary artery hypertension in a patient with compensated cardiac disease: hemodynamic and functional response to sildenafil therapy.

PubMed

Nikolaidis, Lazaros; Memon, Nabeel; O'Murchu, Brian

2015-02-01

We describe the case of a 54-year-old man who presented with exertional dyspnea and fatigue that had worsened over the preceding 2 years, despite a normally functioning bioprosthetic aortic valve and stable, mild left ventricular dysfunction (left ventricular ejection fraction, 0.45). His symptoms could not be explained by physical examination, an extensive biochemical profile, or multiple cardiac and pulmonary investigations. However, abnormal cardiopulmonary exercise test results and a right heart catheterization-combined with the use of a symptom-limited, bedside bicycle ergometer-revealed that the patient's exercise-induced pulmonary artery hypertension was out of proportion to his compensated left heart disease. A trial of sildenafil therapy resulted in objective improvements in hemodynamic values and functional class.

Exercise training preserves vagal preganglionic neurones and restores parasympathetic tonus in heart failure.

PubMed

Ichige, Marcelo H A; Santos, Carla R; Jordão, Camila P; Ceroni, Alexandre; Negrão, Carlos E; Michelini, Lisete C

2016-11-01

Heart Failure (HF) is accompanied by reduced ventricular function, activation of compensatory neurohormonal mechanisms and marked autonomic dysfunction characterized by exaggerated sympathoexcitation and reduced parasympathetic activity. With 6 weeks of exercise training, HF-related loss of choline acetyltransferase (ChAT)-positive vagal preganglionic neurones is avoided, restoring the parasympathetic tonus to the heart, and the immunoreactivity of dopamine β-hydroxylase-positive premotor neurones that drive sympathetic outflow to the heart is reduced. Training-induced correction of autonomic dysfunction occurs even with the persistence of abnormal ventricular function. Strong positive correlation between improved parasympathetic tonus to the heart and increased ChAT immunoreactivity in vagal preganglionic neurones after training indicates this is a crucial mechanism to restore autonomic function in heart failure. Exercise training is an efficient tool to attenuate sympathoexcitation, a hallmark of heart failure (HF). Although sympathetic modulation in HF is widely studied, information regarding parasympathetic control is lacking. We examined the combined effects of sympathetic and vagal tonus to the heart in sedentary (Sed) and exercise trained (ET) HF rats and the contribution of respective premotor and preganglionic neurones. Wistar rats submitted to coronary artery ligation or sham surgery were assigned to training or sedentary protocols for 6 weeks. After haemodynamic, autonomic tonus (atropine and atenolol i.v.) and ventricular function determinations, brains were collected for immunoreactivity assays (choline acetyltransferase, ChATir; dopamine β-hydroxylase, DBHir) and neuronal counting in the dorsal motor nucleus of vagus (DMV), nucleus ambiguus (NA) and rostroventrolateral medulla (RVLM). HF-Sed vs. SHAM-Sed exhibited decreased exercise capacity, reduced ejection fraction, increased left ventricle end diastolic pressure, smaller positive and negative dP/dt, decreased intrinsic heart rate (IHR), lower parasympathetic and higher sympathetic tonus, reduced preganglionic vagal neurones and ChATir in the DMV/NA, and increased RVLM DBHir. Training increased treadmill performance, normalized autonomic tonus and IHR, restored the number of DMV and NA neurones and corrected ChATir without affecting ventricular function. There were strong positive correlations between parasympathetic tonus and ChATir in NA and DMV. RVLM DBHir was also normalized by training, but there was no change in neurone number and no correlation with sympathetic tonus. Training-induced preservation of preganglionic vagal neurones is crucial to normalize parasympathetic activity and restore autonomic balance to the heart even in the persistence of cardiac dysfunction. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Patient with Wolff-Parkinson-White syndrome with intermittent pre-excitation under subarachnoid block for urological surgery

PubMed Central

Garg, Rakesh; Sinha, Renu; Nishad, PK

2011-01-01

Wolff-Parkinson-White (WPW) syndrome is one of the pre-excitation syndromes in which activation of an accessory atrioventricular (AV) conduction pathway leads to bypass the AV node and cause earlier ventricular activation than the normal pathway. We report a patient with intermittent WPW syndrome who repeatedly manifested pre-excitation after subarachnoid block. PMID:21712875

A COMPUTATIONAL APPROACH TO UNDERSTANDING THE CARDIAC ELECTROMECHANICAL ACTIVATION SEQUENCE IN THE NORMAL AND FAILING HEART, WITH TRANSLATION TO THE CLINICAL PRACTICE OF CRT

PubMed Central

Constantino, Jason; Hu, Yuxuan; Trayanova, Natalia A.

2012-01-01

Cardiac resynchronization therapy (CRT) is an established clinical treatment modality that aims to recoordinate contraction of the heart in dyssynchrous heart failure (DHF) patients. Although CRT reduces morbidity and mortality, a significant percentage of CRT patients fail to respond to the therapy, reflecting an insufficient understanding of the electromechanical activity of the DHF heart. Computational models of ventricular electromechanics, are now poised to fill this knowledge gap and provide a comprehensive characterization of the spatiotemporal electromechanical interactions in the normal and DHF heart. The objective of this paper is to demonstrate the powerful utility of computational models of ventricular electromechanics in characterizing the relationship between the electrical and mechanical activation in the DHF heart, and how this understanding can be utilized to devise better CRT strategies. The computational research presented here exploits knowledge regarding the three dimensional distribution of the electromechanical delay, defined as the time interval between myocyte depolarization and onset of myofiber shortening, in determining the optimal location of the LV pacing electrode for CRT. The simulation results shown here also suggest utilizing myocardial efficiency and regional energy consumption as a guide to optimize CRT. PMID:22884712

Assessment of the developmental totipotency of neural cells in the cerebral cortex of mouse embryo by nuclear transfer

PubMed Central

Yamazaki, Yukiko; Makino, Hatsune; Hamaguchi-Hamada, Kayoko; Hamada, Shun; Sugino, Hidehiko; Kawase, Eihachiro; Miyata, Takaki; Ogawa, Masaharu; Yanagimachi, Ryuzo; Yagi, Takeshi

2001-01-01

When neural cells were collected from the entire cerebral cortex of developing mouse fetuses (15.5–17.5 days postcoitum) and their nuclei were transferred into enucleated oocytes, 5.5% of the reconstructed oocytes developed into normal offspring. This success rate was the highest among all previous mouse cloning experiments that used somatic cells. Forty-four percent of live embryos at 10.5 days postcoitum were morphologically normal when premature and early-postmitotic neural cells from the ventricular side of the cortex were used. In contrast, the majority (95%) of embryos were morphologically abnormal (including structural abnormalities in the neural tube) when postmitotic-differentiated neurons from the pial side of the cortex were used for cloning. Whereas 4.3% of embryos cloned with ventricular-side cells developed into healthy offspring, only 0.5% of those cloned with differentiated neurons in the pial side did so. These facts seem to suggest that the nuclei of neural cells in advanced stages of differentiation had lost their developmental totipotency. The underlying mechanism for this developmental limitation could be somatic DNA rearrangements in differentiating neural cells. PMID:11698647

A New MRI-Based Model of Heart Function with Coupled Hemodynamics and Application to Normal and Diseased Canine Left Ventricles

PubMed Central

Choi, Young Joon; Constantino, Jason; Vedula, Vijay; Trayanova, Natalia; Mittal, Rajat

2015-01-01

A methodology for the simulation of heart function that combines an MRI-based model of cardiac electromechanics (CE) with a Navier–Stokes-based hemodynamics model is presented. The CE model consists of two coupled components that simulate the electrical and the mechanical functions of the heart. Accurate representations of ventricular geometry and fiber orientations are constructed from the structural magnetic resonance and the diffusion tensor MR images, respectively. The deformation of the ventricle obtained from the electromechanical model serves as input to the hemodynamics model in this one-way coupled approach via imposed kinematic wall velocity boundary conditions and at the same time, governs the blood flow into and out of the ventricular volume. The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver. The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart. We also discuss the potential of coupled CE and hemodynamics models for various clinical applications. PMID:26442254

Transient left ventricular dysfunction due to coronary spasm after spinal anesthesia with bupivacaine - a case report.

PubMed

Elikowski, Waldemar; Małek-Elikowska, Małgorzata; Słomczyński, Marek; Horbacka, Karolina; Bartkowski, Jarosław; Kalawski, Bartosz

2017-10-23

Bupivacaine is a long-acting local anesthetic (LA) used for cutaneous infiltration, peripheral nerve blocks, epidural and spinal anesthesia. However, its application may result in cardiovascular complications such as: hypotension, bradycardia, cardiac arrest and toxic myocardial injury. The authors describe a 53-year-old male with a history of cigarette smoking, admitted for an elective inguinal hernia surgery. Before surgery, the patient received subarachnoid injection of bupivacaine (20 mg). After the operation, he developed transient hypotension. Blood pressure returned to normal after gelofusine infusion; no sympathomimetics were administered. The male denied chest pain; however, ECG showed ST segment elevation coexisting with left ventricular anterolateral hypokinesia and decreased longitudinal strain in echocardiography. A significant increase in troponin I level was suggestive rather of myocardial infarction than of takotsubo cardiomyopathy. Urgent coronary angiography revealed left anterior descending artery spasm, which remitted after intracoronary nitroglycerin injection. Normalization of ECG and echocardiography was observed within a few days. The authors indicate that the presented atypical adverse effect of bupivacaine manifested itself with delay and that coronary spasm proceeded without angina. A close observation of the patient after anesthetic procedure with LA should be extended over the postoperative period.

Congenital Heart Disease–Causing Gata4 Mutation Displays Functional Deficits In Vivo

PubMed Central

Misra, Chaitali; Sachan, Nita; McNally, Caryn Rothrock; Koenig, Sara N.; Nichols, Haley A.; Guggilam, Anuradha; Lucchesi, Pamela A.; Pu, William T.; Srivastava, Deepak; Garg, Vidu

2012-01-01

Defects of atrial and ventricular septation are the most frequent form of congenital heart disease, accounting for almost 50% of all cases. We previously reported that a heterozygous G296S missense mutation of GATA4 caused atrial and ventricular septal defects and pulmonary valve stenosis in humans. GATA4 encodes a cardiac transcription factor, and when deleted in mice it results in cardiac bifida and lethality by embryonic day (E)9.5. In vitro, the mutant GATA4 protein has a reduced DNA binding affinity and transcriptional activity and abolishes a physical interaction with TBX5, a transcription factor critical for normal heart formation. To characterize the mutation in vivo, we generated mice harboring the same mutation, Gata4 G295S. Mice homozygous for the Gata4 G295S mutant allele have normal ventral body patterning and heart looping, but have a thin ventricular myocardium, single ventricular chamber, and lethality by E11.5. While heterozygous Gata4 G295S mutant mice are viable, a subset of these mice have semilunar valve stenosis and small defects of the atrial septum. Gene expression studies of homozygous mutant mice suggest the G295S protein can sufficiently activate downstream targets of Gata4 in the endoderm but not in the developing heart. Cardiomyocyte proliferation deficits and decreased cardiac expression of CCND2, a member of the cyclin family and a direct target of Gata4, were found in embryos both homozygous and heterozygous for the Gata4 G295S allele. To further define functions of the Gata4 G295S mutation in vivo, compound mutant mice were generated in which specific cell lineages harbored both the Gata4 G295S mutant and Gata4 null alleles. Examination of these mice demonstrated that the Gata4 G295S protein has functional deficits in early myocardial development. In summary, the Gata4 G295S mutation functions as a hypomorph in vivo and leads to defects in cardiomyocyte proliferation during embryogenesis, which may contribute to the development of congenital heart defects in humans. PMID:22589735

The usefulness of left atrial volume index and left ventricular mass index in determining subclinical cardiac involvement in patients with early-stage sarcoidosis.

PubMed

Kasapkara, H A; Şentürk, A; Bilen, E; Duran Karaduman, B; Ayhan, H; Özen, M B; Durmaz, T; Keleş, T; Bozkurt, E

2016-08-01

Sarcoidosis is a multi-systemic granulomatous disease of unknown etiology. The present study has been designed to evaluate the importance of diastolic dysfunction with left atrial volume index (LAVi) and left ventricular mass index (LVMi) in determining subclinical cardiac involvement in subjects with stage I-II pulmonary sarcoidosis. A total of 54 patients under follow-up for sarcoidosis without cardiac involvement and 56 healthy subjects were included in the study. The echocardiographic assessment of the patients revealed no significant difference between the two groups regarding left ventricular end-systolic and end-diastolic diameters, ejection fraction (LVEF) and annular velocity determined by tissue Doppler evaluation. The LVEF calculated was 61.8 ± 7.8 % in the sarcoidosis group versus 64.1 ± 2.7 % in the control group (p = 0.04). Left ventricular interventricular septum thickness, posterior wall thickness, and relative wall thickness were significantly higher in the sarcoidosis group compared to the control group (p < 0.001). The sarcoidosis group had higher LVM and LVMi values compared to the control group (145 ± 18.1 and 79 ± 14 g/m(2), 135 ± 27.7 and 74 ± 14.2 g/m(2); p = 0.020 and p = 0.021, respectively). Left atrial end-systolic volume and LAVi were higher in the sarcoidosis group (28.7 ± 18.5; 15.6 ± 10.2) compared to the control group (16.6 ± 10.9; 8.9 ± 5.5) with a statistically significant difference (p < 0.001). The present study indicates diastolic dysfunction and increased LVMi despite normal systolic function in patients with early-stage sarcoidosis without cardiac involvement. Also, the diastolic parameters were normal without showing any significant difference compared to the control group while there was a statistically significant increase in LAVi. This finding suggests that LAVi may be the earliest marker of diastolic dysfunction in patients with early-stage sarcoidosis without cardiac involvement.

Sustained Accelerated Idioventricular Rhythm in a Centrifuge-Simulated Suborbital Spaceflight.

PubMed

Suresh, Rahul; Blue, Rebecca S; Mathers, Charles; Castleberry, Tarah L; Vanderploeg, James M

2017-08-01

Hypergravitational exposures during human centrifugation are known to provoke dysrhythmias, including sinus dysrhythmias/tachycardias, premature atrial/ventricular contractions, and even atrial fibrillations or flutter patterns. However, events are generally short-lived and resolve rapidly after cessation of acceleration. This case report describes a prolonged ectopic ventricular rhythm in response to high G exposure. A previously healthy 30-yr-old man voluntarily participated in centrifuge trials as a part of a larger study, experiencing a total of 7 centrifuge runs over 48 h. Day 1 consisted of two +Gz runs (peak +3.5 Gz, run 2) and two +Gx runs (peak +6.0 Gx, run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +Gx and +Gz). Hemodynamic data collected included blood pressure, heart rate, and continuous three-lead electrocardiogram. Following the final acceleration exposure of the last Day 2 run (peak +4.5 Gx and +4.0 Gz combined, resultant +6.0 G), during a period of idle resting centrifuge activity (resultant vector +1.4 G), the subject demonstrated a marked change in his three-lead electrocardiogram from normal sinus rhythm to a wide-complex ectopic ventricular rhythm at a rate of 91-95 bpm, consistent with an accelerated idioventricular rhythm (AIVR). This rhythm was sustained for 2 m, 24 s before reversion to normal sinus. The subject reported no adverse symptoms during this time. While prolonged, the dysrhythmia was asymptomatic and self-limited. AIVR is likely a physiological response to acceleration and can be managed conservatively. Vigilance is needed to ensure that AIVR is correctly distinguished from other, malignant rhythms to avoid inappropriate treatment and negative operational impacts.Suresh R, Blue RS, Mathers C, Castleberry TL, Vanderploeg JM. Sustained accelerated idioventricular rhythm in a centrifuge-simulated suborbital spaceflight. Aerosp Med Hum Perform. 2017; 88(8):789-793.

Twenty-year outcome of anomalous origin of left coronary artery from pulmonary artery: management of mitral regurgitation.

PubMed

Kudumula, Vikram; Mehta, Chetan; Stumper, Oliver; Desai, Tarak; Chikermane, Ashish; Miller, Paul; Dhillon, Rami; Jones, Timothy J; De Giovanni, Joseph; Brawn, William J; Barron, David J

2014-03-01

This study is a single-center experience with surgical repair of anomalous origin of left coronary artery from pulmonary artery (ALCAPA) with focus on the management of associated mitral regurgitation (MR). We performed a retrospective analysis of cases presenting to a quaternary referral center between November 1990 and October 2011. In all, 25 patients (18 female) presented with a diagnosis of ALCAPA at a median age of 5 months (range, 1.5 to 102). Twenty-one patients (84%) had moderate to severe impairment of left ventricular function with median fractional shortening of 14% (range, 2% to 33%), and 19 patients (76%) had moderate to severe MR. Surgery was performed with direct coronary reimplantation in 16 patients (64%) and intrapulmonary tunnel (Takeuchi repair) in 9 (36%). Four patients had mitral valve repair at time of surgery, all for structural anomalies. Functional MR with a structurally normal mitral valve was not repaired. The median duration of postoperative follow-up was 93 months (range, 9 to 240). There were no early or late deaths, and no patient required mechanical support. Four patients (16%) required surgical or catheter reintervention. At last follow-up, 24 of 25 patients were asymptomatic; the left ventricular function was normal in 22 patients. Moderate MR was present in 4 patients. There was significant improvement in left ventricular function and MR (p < 0.01) during follow-up. Surgical repair of ALCAPA has good long-term results with low mortality and reintervention rates. The majority of MR is functional and will improve with reperfusion, but structural mitral valve abnormalities should be repaired at the time of surgery. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Global Intracoronary Infusion of Allogeneic Cardiosphere-Derived Cells Improves Ventricular Function and Stimulates Endogenous Myocyte Regeneration throughout the Heart in Swine with Hibernating Myocardium

PubMed Central

Suzuki, Gen; Weil, Brian R.; Leiker, Merced M.; Ribbeck, Amanda E.; Young, Rebeccah F.; Cimato, Thomas R.; Canty, John M.

2014-01-01

Background Cardiosphere-derived cells (CDCs) improve ventricular function and reduce fibrotic volume when administered via an infarct-related artery using the “stop-flow” technique. Unfortunately, myocyte loss and dysfunction occur globally in many patients with ischemic and non-ischemic cardiomyopathy, necessitating an approach to distribute CDCs throughout the entire heart. We therefore determined whether global intracoronary infusion of CDCs under continuous flow improves contractile function and stimulates new myocyte formation. Methods and Results Swine with hibernating myocardium from a chronic LAD occlusion were studied 3-months after instrumentation (n = 25). CDCs isolated from myocardial biopsies were infused into each major coronary artery (∼33×106 icCDCs). Global icCDC infusion was safe and while ∼3% of injected CDCs were retained, they did not affect ventricular function or myocyte proliferation in normal animals. In contrast, four-weeks after icCDCs were administered to animals with hibernating myocardium, %LADWT increased from 23±6 to 51±5% (p<0.01). In diseased hearts, myocyte proliferation (phospho-histone-H3) increased in hibernating and remote regions with a concomitant increase in myocyte nuclear density. These effects were accompanied by reductions in myocyte diameter consistent with new myocyte formation. Only rare myocytes arose from sex-mismatched donor CDCs. Conclusions Global icCDC infusion under continuous flow is feasible and improves contractile function, regresses myocyte cellular hypertrophy and increases myocyte proliferation in diseased but not normal hearts. New myocytes arising via differentiation of injected cells are rare, implicating stimulation of endogenous myocyte regeneration as the primary mechanism of repair. PMID:25402428

Correlation of Arterial Stiffness With Left Atrial Volume Index and Left Ventricular Mass Index in Young Adults: Evaluation by Coronary Computed Tomography Angiography.

PubMed

Osawa, Kazuhiro; Nakanishi, Rine; Miyoshi, Toru; Rahmani, Sina; Ceponiene, Indre; Nezarat, Negin; Kanisawa, Mitsuru; Qi, Hong; Jayawardena, Eranthi; Kim, Nicholas; Ito, Hiroshi; Budoff, Matthew J

2018-04-26

Increased arterial stiffness is reportedly associated with cardiac remodelling, including the left atrium and left ventricle, in middle-aged and older adults. However, little is known about this association in young adults. In total, 73 patients (44 (60%) men) aged 25 to 45 years with suspected coronary artery disease were included in the analysis. The left atrial volume index (LAVI), left ventricular volume index (LVVI), and left ventricular mass index (LVMI) were measured using coronary computed tomography angiography (CCTA). Arterial stiffness was assessed with the cardio-ankle vascular index (CAVI). An abnormally high CAVI was defined as that above the age- and sex-specific cut-off points of the CAVI. Compared with patients with a normal CAVI, those with an abnormally high CAVI were older and had a greater prevalence of diabetes mellitus, higher diastolic blood pressure, greater coronary artery calcification score, and a greater LAVI (33.5±10.3 vs. 43.0±10.3mL/m 2 , p <0.01). In contrast, there were no significant differences in the LVVI or LVMI between the subgroups with a normal CAVI and an abnormally high CAVI. Multivariate linear regression analysis showed that the LAVI was significantly associated with an abnormally high CAVI (standardised regression coefficient=0.283, p=0.03). The present study demonstrated that increased arterial stiffness is associated with the LAVI, which reflects the early stages of cardiac remodelling, independent of various comorbidity factors in young adults with suspected coronary artery disease. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

T-tubule Disruption Promotes Calcium Alternans in Failing Ventricular Myocytes: Mechanistic Insights from Computational Modeling

PubMed Central

Nivala, Michael; Song, Zhen; Weiss, James N.; Qu, Zhilin

2015-01-01

In heart failure (HF), T-tubule (TT) disruption contributes to dyssynchronous calcium (Ca) release and impaired contraction, but its role in arrhythmogenesis remains unclear. In this study, we investigate the mechanisms of TT disruption and other HF remodeling factors on Ca alternans in ventricular myocytes using computer modeling. A ventricular myocyte model with detailed spatiotemporal Ca cycling modeled by a coupled Ca release unit (CRU) network was used, in which the L-type Ca channels and the ryanodine receptor (RyR) channels were simulated by random Markov transitions. TT disruption, which removes the L-type Ca channels from the associated CRUs, results in “orphaned” RyR clusters and thus provides increased opportunity for spark-induced Ca sparks to occur. This effect combined with other HF remodeling factors promoted alternans by two distinct mechanisms: 1) for normal sarco-endoplasmic reticulum Ca ATPase (SERCA) activity, alternans was caused by both CRU refractoriness and coupling. The increased opportunity for spark-induced sparks by TT disruption combined with the enhanced CRU coupling by Ca elevation in the presence or absence of increased RyR leakiness facilitated spark synchronization on alternate beats to promote Ca alternans; 2) for down-regulated SERCA, alternans was caused by the sarcoplasmic reticulum (SR) Ca load-dependent mechanism, independent of CRU refractoriness. TT disruption and increased RyR leakiness shifted and steepened the SR Ca release-load relationship, which combines with down-regulated SERCA to promote Ca alternans. In conclusion, the mechanisms of Ca alternans for normal and down-regulated SERCA are different, and TT disruption promotes Ca alternans by both mechanisms, which may contribute to alternans at different stages of HF. PMID:25450613

T-tubule disruption promotes calcium alternans in failing ventricular myocytes: mechanistic insights from computational modeling.

PubMed

Nivala, Michael; Song, Zhen; Weiss, James N; Qu, Zhilin

2015-02-01

In heart failure (HF), T-tubule (TT) disruption contributes to dyssynchronous calcium (Ca) release and impaired contraction, but its role in arrhythmogenesis remains unclear. In this study, we investigate the effects of TT disruption and other HF remodeling factors on Ca alternans in ventricular myocytes using computer modeling. A ventricular myocyte model with detailed spatiotemporal Ca cycling modeled by a coupled Ca release unit (CRU) network was used, in which the L-type Ca channels and the ryanodine receptor (RyR) channels were simulated by random Markov transitions. TT disruption, which removes the L-type Ca channels from the associated CRUs, results in "orphaned" RyR clusters and thus provides increased opportunity for spark-induced Ca sparks to occur. This effect combined with other HF remodeling factors promoted alternans by two distinct mechanisms: 1) for normal sarco-endoplasmic reticulum Ca ATPase (SERCA) activity, alternans was caused by both CRU refractoriness and coupling. The increased opportunity for spark-induced sparks by TT disruption combined with the enhanced CRU coupling by Ca elevation in the presence or absence of increased RyR leakiness facilitated spark synchronization on alternate beats to promote Ca alternans; 2) for down-regulated SERCA, alternans was caused by the sarcoplasmic reticulum (SR) Ca load-dependent mechanism, independent of CRU refractoriness. TT disruption and increased RyR leakiness shifted and steepened the SR Ca release-load relationship, which combines with down-regulated SERCA to promote Ca alternans. In conclusion, the mechanisms of Ca alternans for normal and down-regulated SERCA are different, and TT disruption promotes Ca alternans by both mechanisms, which may contribute to alternans at different stages of HF. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tricuspid annular plane systolic excursion in dogs with myxomatous mitral valve disease with and without pulmonary hypertension.

PubMed

Poser, H; Berlanda, M; Monacolli, M; Contiero, B; Coltro, A; Guglielmini, C

2017-06-01

To evaluate tricuspid annular plane systolic excursion (TAPSE) in dogs with myxomatous mitral valve disease (MMVD) with or without pulmonary hypertension (PH) and to study the correlations with clinical and echocardiographic parameters. The study population included 99 dogs with MMVD and tricuspid regurgitation. This is a prospective clinical study. All dogs received a transthoracic echocardiographic evaluation, including 2D, M-mode, echo-Doppler, and tissue Doppler measurements. The TAPSE was measured from the left apical four-chamber view and normalized for the effect of body weight (nTAPSE). The dogs were grouped according to the severity of MMVD (American College of Veterinary Internal Medicine guidelines) and presence/absence and severity of PH. Significant differences between TAPSE or nTAPSE and echocardiographic parameters were analyzed among the MMVD and PH severity groups. Correlations between TAPSE or nTAPSE and echocardiographic parameters were calculated. Tricuspid annular plane systolic excursion or nTAPSE were not significantly different among dogs of the MMVD or PH severity groups. Significant correlations were obtained between TAPSE and body weight, left ventricular and atrial dimensions, early diastolic septal and early diastolic and systolic tricuspid annulus velocity (p<0.001); nTAPSE was significantly correlated with normalized end-diastolic left ventricular dimension and fractional shortening (p<0.001). The results show that neither TAPSE nor nTAPSE are reduced in dogs with MMVD with or without PH. It remains unclear if the right ventricle function is not reduced or if a reduced right ventricle function is masked by the contraction of the left ventricle through ventricular interdependence. Copyright © 2017 Elsevier B.V. All rights reserved.

Basic Study and Clinical Implications of Left Ventricular False Tendon. Is it Associated With Innocent Murmur in Children or Heart Disease?

PubMed

Sánchez Ferrer, Francisco; Sánchez Ferrer, María Luisa; Grima Murcia, María Dolores; Sánchez Ferrer, Marina; Sánchez del Campo, Francisco

2015-08-01

Left ventricular false tendon is a structure of unknown function in cardiac physiology that was first described anatomically by Turner. This condition may be related to various electrical or functional abnormalities, but no consensus has ever been reached. The purpose of this study was to determine the time of appearance, prevalence and histologic composition of false tendon, as well as its association with innocent murmur in children and with heart disease. The basic research was performed by anatomic dissection of hearts from adult human cadavers to describe false tendon and its histology. The clinical research consisted of echocardiographic study in a pediatric population to identify any relationship with heart disease, innocent murmur in children, or other abnormalities. Fetal echocardiography was performed prenatally at different gestational ages. False tendon was a normal finding in cardiac dissection and was composed of muscle and connective tissue fibers. In the pediatric population, false tendon was present in 83% on echocardiography and showed a statistically significant association only with innocent murmur in children and slower aortic acceleration. The presence of false tendon was first observed on fetal echocardiography from week 20 of pregnancy. Left ventricular false tendon is a normal finding visualized by fetal echocardiography from week 20 and is present until adulthood with no pathologic effects except for innocent murmur during childhood. It remains to be determined if false tendon is the cause of the murmurs or if its absence or structural anomalies are related to disease. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

[P wave dispersion increased in childhood depending on blood pressure, weight, height, and cardiac structure and function].

PubMed

Chávez-González, Elibet; González-Rodríguez, Emilio; Llanes-Camacho, María Del Carmen; Garí-Llanes, Merlin; García-Nóbrega, Yosvany; García-Sáez, Julieta

2014-01-01

Increased P wave dispersion are identified as a predictor of atrial fibrillation. There are associations between hypertension, P wave dispersion, constitutional and echocardiographic variables. These relationships have been scarcely studied in pediatrics. The aim of this study was to determine the relationship between P wave dispersion, blood pressure, echocardiographic and constitutional variables, and determine the most influential variables on P wave dispersion increases in pediatrics. In the frame of the PROCDEC II project, children from 8 to 11 years old, without known heart conditions were studied. Arterial blood pressure was measured in all the children; a 12-lead surface electrocardiogram and an echocardiogram were done as well. Left ventricular mass index mean values for normotensive (25.91±5.96g/m(2.7)) and hypertensive (30.34±8.48g/m(2.7)) showed significant differences P=.000. When we add prehypertensive and hypertensive there are 50.38% with normal left ventricular mass index and P wave dispersion was increased versus 13.36% of normotensive. Multiple regression demonstrated that the mean blood pressure, duration of A wave of mitral inflow, weight and height have a value of r=0.88 as related to P wave dispersion. P wave dispersion is increased in pre- and hypertensive children compared to normotensive. There are pre- and hypertensive patients with normal left ventricular mass index and increased P wave dispersion. Mean arterial pressure, duration of the A wave of mitral inflow, weight and height are the variables with the highest influence on increased P wave dispersion. Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Polysensory response characteristics of dorsal root ganglion neurones that may serve sensory functions during myocardial ischaemia.

PubMed

Huang, M H; Horackova, M; Negoescu, R M; Wolf, S; Armour, J A

1996-09-01

To determine the response characteristics of dorsal root ganglion neurones that may serve sensory functions during myocardial ischaemia. Extracellular recordings were made from 54 spontaneously active and 5 normally quiescent dorsal root ganglion neurones (T2-T5) in 22 anaesthetized open-chest dogs under control conditions and during epicardial mechanical or chemical stimulation and myocardial ischaemia. The activity of 78% of spontaneously active and all quiescent neurones with left ventricular sensory fields was modified by left ventricular ischaemia. Forty-six spontaneously active neurones (85%) were polysensory with respect to mechanical and chemical stimuli. The 5 quiescent neurones responded only to chemical stimuli. Spontaneously active neurones associated with left ventricular mechanosensory endings (37 neurones) generated four different activity patterns in response to similar mechanical stimuli (high or low pressure active, high-low pressure active, high-low pressure inactive). A fifth group generated activity which was not related to chamber dynamics. Adenosine, adenosine 5'-triphosphate, substance P and bradykinin modified 72, 61, 65 and 63% of the spontaneously active neurones, respectively. Maximum local mechanical or chemical stimuli enhanced activity to similar degrees, as did ischaemia. Each ischaemia-sensitive neurone displayed unique activity patterns in response to similar mechanical or chemical stimuli. Most myocardial ischemia-sensitive dorsal root ganglion neurones associated with epicardial neurites sense mechanical and multiple chemical stimuli, a small population sensing only mechanical or chemical stimuli. Activity patterns generated by these neurones depend on their primary sensory characteristics or those of other neurones that may converge on them, as well as the type and magnitude of the stimuli that impinge upon their sensory fields, both normally and during ischaemia.

True Anemia-Red Blood Cell Volume Deficit-in Heart Failure: A Systematic Review.

PubMed

Montero, David; Lundby, Carsten; Ruschitzka, Frank; Flammer, Andreas J

2017-05-01

Anemia in heart failure (HF) is commonly diagnosed according to hemoglobin concentration [Hb], hence may be the result of hemodilution or true red blood cell volume (RBCV) deficit. Whether true (nonhemodilutional) anemia in HF can or cannot be generally inferred by [Hb] measurements and clinical correlates remains unclear. The purpose of this study was to systematically review the literature and investigate the status and correlates of RBCV in patients with HF. MEDLINE, Scopus, and Web of Science were searched since their inceptions until April 2016 for articles directly reporting or allowing the calculation of intravascular volumes (RBCV, plasma volume) in patients with HF according to the International Council for Standardization in Hematology. Eighteen studies were included after systematic review, comprising a total of 368 patients with HF (limits for mean age=49-80 years, sex=0%-92% females, left ventricular ejection fraction=26%-61%). Mean RBCV was reduced (limits=67%-88% of normal) in all studies including HF patients with anemia (low [Hb]) (7 studies, n=127), whereas only 2 of 10 studies in nonanemic patients with HF presented lower than normal mean RBCV (90% and 96%). In metaregression analyses, RBCV was positively associated with [Hb] ( B =6.10, SE=1.44) and negatively associated with age ( B =-1.14, SE=0.23), % females ( B =-0.38, SE=0.04), left ventricular ejection fraction ( B =-0.81, SE=0.20), and body mass index ( B =-3.55, SE=0.46; P <0.001). Presence or absence of true anemia in patients with HF as determined by RBCV status mainly concurs with diagnosis based on [Hb] and presents negative relationships with age, female sex, left ventricular ejection fraction, and body mass index. © 2017 American Heart Association, Inc.

Natural history of severe aortic stenosis: Diastolic wall strain as a novel prognostic marker.

PubMed

Obasare, Edinrin; Bhalla, Vikas; Gajanana, Deepakraj; Rodriguez Ziccardi, Mary; Codolosa, Jose N; Figueredo, Vincent M; Morris, Dennis Lynn; Pressman, Gregg S

2017-04-01

Diastolic wall strain (DWS) has been proposed as a simple noninvasive measure of left ventricular (LV) stiffness. This study investigated DWS as a possible predictor of mortality in severe aortic stenosis (AS). 138 patients with severe AS (indexed aortic valve area [AVA]<0.6 cm 2 /m 2 ) and normal ejection fraction (>55%) were included. 52 patients (38%) had aortic valve interventions or poor image quality (n=5) and were excluded leaving 86 in the study group (84±8 years, 70% female, 69% African American). DWS was defined as (LVPWs-LVPWd)/LVPWs where LVPWs=left ventricular posterior wall thickness in systole and LVPWd=left ventricular wall thickness in diastole. Follow-up extended 2.0±1.9 years (median 1.6 years). Mean DWS for the group was 0.21±0.11 (normal=0.4±0.07). In patients who died, DWS was significantly lower than in survivors (0.18±0.09 vs 0.24±0.11, P=.02). By contrast, traditional measures of diastolic dysfunction did not predict death. Regression analysis showed DWS predicted death even after adjusting for age, sex, race, indexed AVA, symptoms (angina, shortness of breath, dizziness, syncope), and clinical factors (creatinine, smoking, diabetes, hypertension, hyperlipidemia) (HR 2.5 [95% CI 1.02-5.90], P<.05). The best cutoff value for DWS of 0.25 had a sensitivity of 42% and specificity of 83% for predicting death. DWS is an independent predictor of all-cause mortality in patients with severe AS, even after accounting for traditional clinical and echocardiographic parameters. © 2017, Wiley Periodicals, Inc.

Left ventricular remodeling and change of systolic function after closure of patent ductus arteriosus in adults: device and surgical closure.

PubMed

Jeong, Young-Hoon; Yun, Tae-Jin; Song, Jong-Min; Park, Jung-Jun; Seo, Dong-Man; Koh, Jae-Kon; Lee, Se-Whan; Kim, Mi-Jeong; Kang, Duk-Hyun; Song, Jae-Kwan

2007-09-01

Left ventricular (LV) remodeling and predictors of LV systolic function late after closure of patent ductus arteriosus (PDA) in adults remain to be clearly demonstrated. In 45 patients with PDA, including 28 patients who received successful occlusion using the Amplatzer device (AD group) (AGA, Golden Valley, MN) and 17 patients who received surgical closure (OP group), echocardiography studies were performed before closure and 1 day (AD group) or within 7 days (OP group) after closure, and then were repeated at > or = 6 months (17 +/- 13 months). In both groups, LV ejection fraction (EF) and end-diastolic volume index were significantly decreased immediately after closure, whereas end-systolic volume index did not change. During the long-term follow-up period, end-systolic as well as end-diastolic volume indices decreased significantly in both groups and LV EF recovered compared to the immediate postclosure state. However, LV EF remained low compared to the preclosure state. Five patients (11.1%) including 3 patients in the AD group and 2 patients in the OP group showed persistent late LV systolic dysfunction (EF <50%). In stepwise, multiple logistic regression analysis, preclosure EF was the only independent predictor of late normal postclosure EF (odds ratio, 1.230; 95% CI, 1.054-1.434; P = .008). Receiver operating characteristic curve analysis showed that preclosure EF > or = 62% had a sensitivity of 72% and a specificity of 83% for predicting late normal LV EF after closure. Left ventricular EF remains low late after PDA closure compared with preclosure state in adults. Preclosure LV EF is the best index to predict late postclosure LV EF.

Association between left ventricular mechanics and diffuse myocardial fibrosis in patients with repaired Tetralogy of Fallot: a cross-sectional study.

PubMed

Haggerty, Christopher M; Suever, Jonathan D; Pulenthiran, Arichanah; Mejia-Spiegeler, Abba; Wehner, Gregory J; Jing, Linyuan; Charnigo, Richard J; Fornwalt, Brandon K; Fogel, Mark A

2017-12-11

Patients with repaired tetralogy of Fallot (TOF) have progressive, adverse biventricular remodeling, leading to abnormal contractile mechanics. Defining the mechanisms underlying this dysfunction, such as diffuse myocardial fibrosis, may provide insights into poor long-term outcomes. We hypothesized that left ventricular (LV) diffuse fibrosis is related to impaired LV mechanics. Patients with TOF were evaluated with cardiac magnetic resonance in which modified Look-Locker (MOLLI) T1-mapping and spiral cine Displacement encoding (DENSE) sequences were acquired at three LV short-axis positions. Linear mixed modeling was used to define the association between regional LV mechanics from DENSE based on regional T1-derived diffuse fibrosis measures, such as extracellular volume fraction (ECV). Forty patients (26 ± 11 years) were included. LV ECV was generally within normal range (0.24 ± 0.05). For LV mechanics, peak circumferential strains (-15 ± 3%) and dyssynchrony indices (16 ± 8 ms) were moderately impaired, while peak radial strains (29 ± 8%) were generally normal. After adjusting for patient age, sex, and regional LV differences, ECV was associated with log-adjusted LV dyssynchrony index (β = 0.67) and peak LV radial strain (β = -0.36), but not LV circumferential strain. Moreover, post-contrast T1 was associated with log-adjusted LV diastolic circumferential strain rate (β = 0.37). We observed several moderate associations between measures of fibrosis and impaired mechanics, particularly the LV dyssynchrony index and peak radial strain. Diffuse fibrosis may therefore be a causal factor in some ventricular dysfunction in TOF.

Computational modelling of left-ventricular diastolic mechanics: effect of fibre orientation and right-ventricle topology.

PubMed

Palit, Arnab; Bhudia, Sunil K; Arvanitis, Theodoros N; Turley, Glen A; Williams, Mark A

2015-02-26

Majority of heart failure patients who suffer from diastolic dysfunction retain normal systolic pump action. The dysfunction remodels the myocardial fibre structure of left-ventricle (LV), changing its regular diastolic behaviour. Existing LV diastolic models ignored the effects of right-ventricular (RV) deformation, resulting in inaccurate strain analysis of LV wall during diastole. This paper, for the first time, proposes a numerical approach to investigate the effect of fibre-angle distribution and RV deformation on LV diastolic mechanics. A finite element modelling of LV passive inflation was carried out, using structure-based orthotropic constitutive law. Rule-based fibre architecture was assigned on a bi-ventricular (BV) geometry constructed from non-invasive imaging of human heart. The effect of RV deformation on LV diastolic mechanics was investigated by comparing the results predicted by BV and single LV model constructed from the same image data. Results indicated an important influence of RV deformation which led to additional LV passive inflation and increase of average fibre and sheet stress-strain in LV wall during diastole. Sensitivity of LV passive mechanics to the changes in the fibre distribution was also examined. The study revealed that LV diastolic volume increased when fibres were aligned more towards LV longitudinal axis. Changes in fibre angle distribution significantly altered fibre stress-strain distribution of LV wall. The simulation results strongly suggest that patient-specific fibre structure and RV deformation play very important roles in LV diastolic mechanics and should be accounted for in computational modelling for improved understanding of the LV mechanics under normal and pathological conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mitral annular plane systolic excursion/left ventricular length (MAPSE/L) as a simple index for assessing left ventricular longitudinal function in children.

PubMed

Terada, Tomomasa; Mori, Kazuhiro; Inoue, Miki; Yasunobu, Hayabuchi

2016-11-01

Assessment of longitudinal left ventricular (LV) function is important for early detection of cardiac dysfunction. Although mitral annular plane systolic excursion (MAPSE) obtained by M-mode echocardiography offers a simple method for assessing longitudinal LV function, normal values of MAPSE for children change according to body size. To minimize the effects of body size, MAPSE was divided by LV long-axis length (MAPSE/L). MAPSE/L was measured in 210 healthy children from birth to 15 years of age and classified into five subgroups. MAPSE/L was then compared with 10 parameters in 136 children (age, heart rate, mean blood pressure, ejection fraction of the LV (EF), peak atrial flow velocity/peak early diastolic flow velocity of mitral flow, tissue Doppler velocity during systole (s') and early diastole (e'), E/e' ratio, Tei index, and global longitudinal strain (GLS) of the LV by the speckle tracking method). MAPSE/L was significantly lower in the neonate group than in the remaining four groups. MAPSE/L then increased with age to peak at 1-5 years and gradually decreased thereafter. In all cases beyond the neonatal period, MAPSE/L was more than 0.17. Among various parameters, GLS, age, EF, Tei index and s' were significantly associated with MAPSE/L in that order. In univariate analysis, GLS was most significantly associated with MAPSE/L (r=.56). We have established normal reference values for MPSE/L in healthy children. MAPSE/L is expected to offer a simple parameter to evaluate LV longitudinal systolic function during daily routine echocardiography in children. © 2016, Wiley Periodicals, Inc.